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Home My WebLink AboutCOM 0329.000 1998-2000RECE iVED '99 JUN 7 PM 1135 COUNTY CLERK COUNTY OF HAWAII HC 2 Box 9575 Keaau, Hawaii 96749 (808) 982-5831 To: Recipients of Draft EA From: Ron Terry, Geometrician Associates Date: June 3, 1999 Subject: Draft Environmental Assessment for Kawailani Street Improvements, South Hilo District, Island of Hawaii Attached is the Draft Environmental Assessment (EA) for the proposed project. Our firm along with the agencies listed below invite your participation and comments on the EA. Please note that the 30 -day comment period for the project begins on June 8, 1999. If you wish to submit comments on the EA, please send them to one (or more) of the addresses below, postmarked no later than July 8, 1999. A public meeting on the project will be held on Thursday, June 17, at 6:30 PM, in Campus Center 301 at the University of Hawaii at Hilo. Please contact me at (808) 982-5831 or Galen Kuba of the Hawaii County Department of Public Works at (808) 961-8327 for further details. Thank you for your participation in the Environmental Assessment process Mr. Abraham Wong, Division Administrator Mr. Kazu Hayashida, Director Mr. Jiro Sumada, Deputy Chief Eng Federal Highway Administration State Department of Transportation Hawaii County Dept. of Public Works P.O. Box 50206 Highways Division 25 Aupum Street 300 Ala Moana Boulevard 869 Punchbowl Street Hilo, Hawaii 96720 Honolulu, Hawaii 96850 Honolulu, Hawaii 96813 (808) 541-2700 (808) 587-2220 (808) 961-8321 Mr. Colin Hashiro Director okahara & Associates Hawaii State Office of Environmental 200 Kohola Street Quality Control Hilo, Hawaii 96720 235 S. Beretania St., Suite 702 (808) 961-5527 Honolulu, Hl 96813 Note: Attaciunent is on'file in the Clerk's Office. Comm. No. ✓ FileNo. F r%1D/C.IP Ref. To: P C Ref. Date JUN 71999 Hawaii County Council 2_5 Aupu;li Street Hilo, Haxan 96720 KAWAILANI STREET IMPROVEMENTS IWALANI TO POHAKULANI STREET SOUTH HILO, HAWAII ENVIRONMENTAL ASSESSMENT May 1999 Submitted Pursuant to the National Environmental Policy Act (NEPA), 42 U.S.C. 4332 (2)(c), Section 4(t) of the Department of Transportation Act (DOT) 49 U.S.C. 303, and Chapter 343, Hawaii Revised Statutes (HRS) U.S. Department of Transportation, Federal Highway Administration (FHWA) State of Hawaii, Department of Transportation, Highways Division County of Hawaii, Department of Public Works C -3a9 KAWAILANI STREET IMPROVEMENTS IWALANI TO POHAKULANI STREET SOUTH HILO, HAWAH ENVIRONMENTAL ASSESSMENT Submitted Pursuant to the National Environmental Policy Act (NEPA), 42 U.S.C. 4332 (2)(c), 49 U.S.C. 303, and Chapter 343, Hawaii Revised Statutes (HRS) U.S. Department of Transportation, Federal Highway Administration (FHWA) State of Hawaii, Department of Transportation, Highways Division County of Hawaii, Department of Public Works ,g% 9 /99 Date of Approval Jiro S mada, eputy Chief Engineer Hawaii u y Department of Public Works Date of Approval Kazu Hayashida, Director Hawaii State Department of Transportation Dat6 of Approval C,,—Abrah2lA Wong, Division Administrator Federal Highway Administration The following persons may be contacted for additional information concerning this document Mr. Abraham Wong, Division Administrator Mr. Kazu Hayashida, Director Mr. Jiro Sumada, Dept. Chief Engineer Federal Highway Administration State Department of Transportation Hawaii County Dept. of Public Works P.O. Box 50206 Highways Division 25 Aupuni Street 300 Ala Moana Boulevard 869 Punchbowl Street Hilo, Hawau 96720 Honolulu, Hawaii 96850 Honolulu, Hawaii 96813 (808)541-2700 (808)587.2220 (808)961-8321 The proposed project would provide widening, channelized lanes, and traffic signals at the intersections of Ainaola Drive and lwalani Street with Kawailani Street, in Hilo, Hawaii. The purpose of the project is to redesign the intersections in such a way as to maximize traffic safety and minimize peak hour traffic congestion. Noise impacts would occur but can be largely mitigated through noise reduction barriers. Air quality would benefit as a result of the improvements. Right- of-way taking would affect adjacent residences, public use structures, and businesses. COMMENTS are due Kawailani Intersection Improvements SUMMARY PROJECT DESCRIPTION, PURPOSE AND NEED, AND ALTERNATIVES The proposed project would improve two closely spaced intersections on Kawailani Street - Iwalani Street and Ainaola Drive/Pohakulani Street - in Hilo, Island of Hawaii (See Fig. 1-I). Ainaola Drive, Kawailani Street and Iwalani Streets function as collector roads conducting most of the traffic from Hilo's upland suburb of Waiakea Uka to and from schools, workplaces and shopping areas. Therefore, these roads exhibit high peak hour traffic counts relative to other County roads in Hilo and are often congested during AM and/or PM peak hours. The less than optimal geometry and spacing of these intersections have led to greater than normal accident rates. A recent comprehensive study of problem intersections in Hilo determined that the Kawailani-Iwalani Street intersection ranked high in accidents among Hilo intersections and met warrants for traffic signal installation. There are four Build Alternatives for the project: IA, 1B, 2A, and 2B (See Fig. 2-1). Common to all Build Alternatives are the following elements: o Signalization of the intersections of Ainaola Drive and Iwalani Street with Kawailani Street; o Provision of additional through and turn lanes on sections of Kawailani Street and on Ainaola Drive approaching the intersections, including full opposed left - turn lanes on Kawailani Street at both intersections. o Travel lanes 3.4 m (11.0 ft.) in width, a paved shoulder 1.5 m (5.0 ft.) in width, and paved swales 1.5 m (5.0 ft.) in width. o Replacement and upgrade of street lighting and drainage structures in conformance with federal and County standards. Alternatives IA/2A differ from Alternatives IB/2B in the treatment of turning movements at the intersections. Alternatives lA/lB involve realignment of the southern leg of Pohakulani Street 110 m (360 ft.) to the south; Alternatives 2A/2 B would place a cul-de-sac at the former intersection of Pohakulani Street and Ainaola Drive and provide a new access way to Ainaola Drive through a vacant lot. Alternatives lA/lB differ from Alternatives 2B/2A in the treatment of various turning lanes on Kawailani Street. The purpose of the project is to redesign the intersections in such a way as to maximize traffic safety and minimize peak hour traffic congestion. The project would not, and is not intended to, increase the capacity of the general roadway system that feeds the intersections, as most Environmental Assessment S-1 Summary Kawailani Intersection Improvements segments of this system operate at acceptable Levels of Service. COST AND SCHEDULE Depending on the Alternative selected, the project would cost between $2.12 and $2.42 million. With necessary approvals, the project would begin construction in early 2000 and would last approximately 1 year. LEAD AGENCIES AND ACCEPTING AUTHORITY The Federal Highway Administration (FHWA), the Hawaii State Department of Transportation (HDOT) and the Hawaii County Department of Public Works (DPW) are serving as joint lead agencies to prepare an Environmental Assessment (EA) in compliance with federal and State of Hawaii requirements. The approving authorities for the EA are the Hawaii Division Administrator of FHWA and the Director of HDOT. AFFECTED ENVIRONMENT Project Location and Neighborhood Character The project is located within the city of Hilo, which encloses about 50 square km (20 square mi.) (See Fig. 1-1). Locations potentially affected by the physical characteristics of the road (pavement, noise, runoff, carbon monoxide gas, etc.) are restricted to a zone within about 200 in (650 ft.) of the Ainaola Drive/Kawailani Street intersection. The project site is a residential neighborhood in the Waiakea area with a small commercial center comprising a convenience store, a video store and a gas station. Census data reveal that the project site is near the average for Hilo in most demographic measures, except for its somewhat higher home values, incomes and rents. Floodplain Status and Water Quality No floodways or floodplain are present, and the entire area is mapped as Zone X, defined as areas of moderate or minimal flood hazard on the Flood Insurance Rate Maps. No streams are located near the project site. Runoff generated from the site is typical of urban areas. Environmental Assessment S-2 Summary Kawailani Intersection Improvements Air Quality and Noise Regional air quality is good, and there are no concentrations of pollutants exceeding state or federal standards. The entire State of Hawaii is an attainment area with respect to federal regulations. Traffic noise is fairly high for residences near the intersections (58-65 L,) but does not approach or exceed the federal Noise Abatement Criteria of 67 L, for residential or commercial areas. Biology and Wetlands The project area is completely urbanized and does not contain any natural vegetation, habitat for native species, streams, wetlands or aquatic sites, or other areas that might be of concern for biological impacts Land Use Designation The area is entirely within the State Land Use Urban District. County zoning is Residential and Village Commercial. The site is not located within or near the Special Management Area of the Hawaii Coastal Zone Management Program. Historic Sites All land in the project site has been completely altered by construction or clearing within the last 30 years. There are no known structures or remains dating from before this period. No historic sites appear to be present, and none are listed in the U.S. or Hawaii Registers of Historic Places in or near the project site. Public Facilities and Services The Waiakea Fire Station is located near the Iwalani Street intersection. No other public parks or facilities are present in the area. Agricultural Resources Soil on the project site is classified as Olaa Extremely Stony Silty Clay Loam. This soil is rapidly permeable with slow runoff, and erosion hazard is thus slight. Areas of this soil type in the project area were formerly farmed in sugar cane and now support some pasture or diversified tree crops. Environmental Assessment S-3 Summary Kawailani Intersection Improvements Traffic Circulation and Safety Currently, these unsignalized intersections are congested during AM and/or PM peak hours. The less than optimal geometry and spacing of these intersections have led to greater than normal accident rates. Bicycle and Pedestrian Facilities No sidewalks or bicycle facilities are currently present at the project site. The Bike Plan Hawaii designates Kawailani Street as a future proposed bike route, and Ainaola Drive is a future proposed bike lane. ENVIRONMENTAL IMPACTS The expected environmental impacts of the project and proposed mitigation are presented below and summarized in Table S-1. Except for impacts related to construction, the discussion considers impacts from 1998 through the year 2018. In this summary, the Build Alternatives are distinguished only where differences in impacts exist. Floodplain and Water Quality Impacts As no floodplain are present, no impacts are expected to occur. There would be negligible impact to water quality, as the area is already completely urbanized. No sensitive resources such as streams, ponds or wetlands are present on or near the project site. Air Quality The No -Build Alternative would lead to a slight exceedance of state air quality standards for carbon monoxide during the afternoon peak traffic hour. Under the Build Alternative, impacts to regional (mesoscale) and onsite (microscale) air quality would be somewhat beneficial because of the predicted decrease in congestion and queuing. No exceedance of State of Hawaii or federal air quality standards would occur, and therefore no mitigation is necessary. Noise Under the No Build Alternative, no home or business would would experience noise increases exceeding 15 dB or absolute levels above 66 Lq at either the AM or PM peak hours. Therefore no noise impacts of a magnitude large enough to necessitate consideration of Environmental Assessment S-4 Smeary Kawailani Intersection Improvements mitigation measures would occur. By contrast, all Build Alternatives would cause noise impacts: IA: 4 residences; 2A: 5; lB and 2B: 6 residences each. The magnitude of the impact is in all cases small, with the maximum predicted noise level at any receptor less than 68.0 Lw. A series of noise absorbing walls with heights between 1.7 m and 2.1 in (5.5 to 7.0) would be able to achieve sound reductions greater than 5.0 dBA at all impacted residences. However, a cost of over $35,000 per protected property at one of the residences exceeds the cost considered reasonable and precludes their use at this location. Biology and Wetlands The U.S. Fish and Wildlife Service has determined that no threatened or endangered species are known to occur in the project area and no significant adverse impacts to fish and wildlife resources are expected to result from the proposed project. Consistency With Planning The proposed project is consistent with all planning. No rezoning, reclassification or use permits are required. Socioeconomic Impacts and Relocation The project is not expected to adversely impact the identity or cohesion of this community. Although the widened profile will increase the "barrier effect" of Kawailani Street, traffic signals and crosswalks will promote safer use by pedestrians. No minority or low-income groups would experience disproportionately high adverse impacts either directly or indirectly through construction -phase impacts, right-of-way taking, long-term noise and air quality effects, or other adverse effects. No relocations would occur as a result of the project. Historic Sites The SHPO issued a letter on 13 July 1998 stating that no effects to significant historic sites would likely occur as a result of the road construction (see Appendix 4 for coordination letter). Environmental Assessment S-5 Summary Kawailani Intersection Improvements Table S-1 Summary of Impacts and Proposed Mitigation Measures Build Versus No-Ruild Alfprnahivac pact Category F No -Build Alternative Build Alternative lA 1B 2A 2B Floodplain & Water Quality No impact. Negligible impact to urbanized area, no Floodplain. [No difference among Build Alternatives] Air Quality Carbon monoxide exceeding No exceedance of state standards state standards ]No difference among Build Alternativesl Noise Noise increase not great enough to produce noise Noise increase approaching or exceeding 67 LN 4 residences 6 res. S res. 6 res. impacts. mitigable through noise barriers at 3 residences 4 res. 3 res. 4 res. Biology/Wetlands No impact. Noun act. Planning No impact. No impact. Relocation No impact. No impact. Socioeconomic No impact. Negligible impact to community cohesion. Historic Sites No impact. No impact. Public Facilities No impact. Acquisition of frontage at Waiakea Fire Station. Agricultural Land No impact. No impact. Traffic Worsened congestion, Improvement in traffic and increased safety. LOS of C or Circulation & Safety inefficient circulation & high accident rate. LOS of C or better at peak hours for nearly all movements. worse at peak hours for most turning movements. Each Alternative has advantages and disadvantages; none clearly superior. Pedestrian and No provision of shoulder for Provision of shoulder to accommodate Bicycle Facilities sidewalk & bike use. both pedestrians and bicycles. Energy Inefficient travel/ increased Efficient travel leading to decreased energy consumption. energy consumption. Construction No impact. Noise, vehicle emission, traffic & access impacts, affecting mostly houses with frontage on project. Mitigable through scheduling limitation & noise permit condition. (No substantial difference among Build Alternatives] Growth/Cumu- No impact. No impact. Environmental Assessment S-6 Summary Kawailani Intersection Improvements Public Facilities and Services In general, police, fire and emergency medical services will benefit from the project because it will reduce accidents and congestion at the intersection. However, widening would require taking of about 3 m (10 ft.) in front of the Waiakea Fire Station. Agricultural Resources The area is classified in the Agricultural Lands of Importance to the State of Hawaii (ALISH) map series as urban, and no Prime, Unique, or Other Important Lands are present. Traffic Circulation and Safety The selection of any Build Alternative would lead to generally adequate or better Levels of Service for all movements of the two project intersections at both the AM and PM peak hours. The No Build Alternative would lead to unacceptable Levels of Service for most movements of both intersections. Level of Service in Alternatives IA/2A differs in a number of ways from that for 1B/2B at individual turning movements, but each scheme has its advantages and disadvantages. Alternatives 2A/2B lengthen (and thus improve) the separation of the now closely -spaced intersections of Kawailani Street and Pohakulani Street with Ainaola Drive by 110 m (360 ft.). Bicycle and Pedestrian Facilities There is insufficient width to allow construction of separate bicycle and pedestrian facilities. The project will therefore involve provision of 1.5 m (5.0 ft.) shoulders on Kawailani Street and Ainaola Drive to accommodate both pedestrians and bicyclists. Energy The No Build Alternative would perpetuate inefficient engine operation, leading to increased energy consumption. The Build Alternative would decreased energy consumption. Secondary, Cumulative and Growth -Inducing Impacts There is negligible potential for growth -induction in the project area because of a safety related improvement such as the proposed project. The adverse effects of the project are very limited in severity and geographic scale. There are no projects being undertaken nearby which would combine with the Kawailani/Ainaola project to produce cumulative impacts. Environmental Assessment S-7 Summary Kawailani Intersection Improvements Construction -Phase Impacts Construction of the proposed project would last approximately one year. During this period construction vehicles, power tools and heavy equipment would generate noise, traffic congestion, exhaust emissions and the potential for soil erosion. Residents and others with property directly adjacent to the improvements would be the most directly affected by construction. This group includes a total of less than 30 residences, the small commercial center with a convenience store, a video store and a gas station. A number of mitigation measures will be incorporated into Special Contract Requirements or will be implemented as part of permits. The construction contractor will be required to: o Adhere to a specific set of Best Management Practices for avoidance/reduction of soil erosion and off-site sediment transport; o Develop and implement a Dust Control Plan, to be reviewed by the Hawaii State Department of Health; o Move construction equipment and workers between the site and a nearby staging area during off-peak traffic hours; o Conform with Title 11, Chapter 46, HAR (Community Noise Control) and obtain a permit with suitable mitigation measures; o Utilize professional traffic control throughout construction and keep intersections open during the AM and PM peak hours, i.e., from 7:00-8:00 AM and between 4:30 - 5:30 PM; and o Coordinate with utility companies to schedule disruption so as to minimize the inconvenience to utilities and their customers. Coastal Zone Management Program The entire State of Hawaii is considered to lie within the Coastal Zone. As such, all federal projects are subject to review for consistency with the policies and objectives of the Hawaii Coastal Zone Management Program. The Hawaii County Department of Public Works believes that the project does not impact these coastal zone resources and is consistent with the objectives of the program. This Draft EA will be reviewed by the Hawaii Department of Business, Economic Development, and Tourism, Office of Planning to help determine such consistency. Environmental Assessment S-8 Summary Kawailani Intersection Improvements TABLE OF CONTENTS SUMMARY................................................ S-1 TABLE OF CONTENTS .......................................... i LIST OF TABLES ............................................. LIST OF FIGURES ............................................ LIST OF APPENDICES ......................................... I PROJECT LOCATION, PURPOSE AND NEED ................. 1-1 1.1 Project Location .................................... l-1 1.2 Lead Agencies ..................................... l-1 1.3 Project Purpose and Need .............................. 1-1 2 DESCRIPTION OF ALTERNATIVES ......................... 2-1 2.1 Build Alternatives: Description, Cost and Schedule .............. 2-1 2.2 No -Build Alternative ................................. 2-7 2.3 Alternatives Evaluated and Withdrawn from Further Consideration .... 2-7 3 ENVIRONMENTAL SETTING AND IMPACTS . ................. 3-1 3.1 Motorized Vehicle Transportation Patterns and Traffic Safety ....... 3-2 3. 1.1 Peak Hour Traffic Volumes and Level of Service ............ 3-2 3.1.2 Current and Future Safety Conditions .................. 3-4 3.2 Physical Environment ................................ 3-5 3.2. l Geology and Hazards ............................ 3-5 3.2.2 Hydrology, Floodplains and Water Quality .............. 3-6 3.2.3 Climate and Air Quality .......................... 3-7 3.2.4 Noise Levels ................................. 3-10 3.3 Biological Environment and Wetlands ...................... 3-17 3.4 Socioeconomic ..................................... 3-18 3.4.1 Community Identity and Right -of -Way Acquisition ......... 3-18 3.4.2 Planning .................................... 3-21 3.4.3 Land Use ................................... 3-22 3.4.4 Public Services and Facilities ....................... 3-22 3.4.5 Historic Sites/Archaeological Resources ................ 3-23 3.4.6 Agricultural Land and Soils ........................ 3-23 3.4.7 Pedestrian and Bicycle Transportation Patterns ............ 3-23 3.4.8 Secondary, Growth -Inducing and Cumulative Impacts ....... 3-24 3.4.9 Coastal Zone Management Act (CZMA) ................ 3-24 3.5 Construction Phase Impacts ............................. 3-25 3.5.1 Sediments, Water Quality and Flooding ................ 3-25 3.5.2 Air Quality .................................. 3-26 3.5.3 Noise ...................................... 3-27 3.5.4 Traffic Congestion .............................. 3-28 3.5.5 Public Utilities ................................ 3-28 3.6 Required Permits and Approvals ......................... 3-29 Environmental Assessment t Table of Contents Kawailani Intersection Improvements 4 COMMENTS AND COORDINATION ......................... 4-1 4.1 Agencies Contacted .................................. 4-1 4.2 Public Involvement .................................. 4-3 4.3 Coordination Correspondence ........................... 4-3 5 LIST OF DOCUMENT PREPARERS .......................... 5-1 6 STATE OF HAWAII ENVIRONMENTAL ASSESSMENT FINDINGS .... 6-1 REFERENCES.........................................R-1 LIST OF TABLES Table 2-I Comparison of Costs and Right -of -Way Take for Build Alternatives .... 2-7 Table 3-1 Current and Future Level of Service at Major Project Intersections .. 3-3 Table 3-2 Estimated Worst -Case 1 -Hour Carbon Monoxide Concentrations ..... 3-9 Table 3-3 Estimated Worst -Case 8 -Hour Carbon Monoxide Concentrations ..... 3-10 Table 3-4 Traffic Noise Measurements and Model Predictions, Selected Sites .... 3-11 Table 3-5 Noise Impacts and Mitigation ............................ 3-16 Table 3-6 Noise Mitigation Barrier Cost ............................. 3-17 Table 3-7 1990 U.S. Census Data, Census Tracts and Block Groups ......... 3-20 LIST OF FIGURES Figure 1-1 Project Location ..................................... 1-2 Figure 2 -la Alternative IA ...................................... 2-2 Figure 2-1b Alternative 1B ...................................... 2-3 Figure 2 -lc Alternative 2A ...................................... 2-4 Figure 2-ld Alternative 2B ...................................... 2-5 Figure 2-2 Typical Cross Section ................................. 2-6 Figure 3-1 Noise Measurement Sites ................................ 3-12 Figure 3-2a Noise Impacts and Mitigation, Alternatives IA and 1B ............. 3-14 Figure 3-2b Noise Impacts and Mitigation, Alternatives 2A and 2B ............. 3-15 Figure 3-3 Census Tracts and Block Groups ........................... 3-19 LIST OF APPENDICES Appendix 1 Traffic Assessment Appendix 2 Air Quality Study Appendix 3 Acoustic Study Appendix 4 Agency Comments and Public Involvement Appendix 5 List of Properties Affected by Right -of -Way Taking Environmental Assessment ii Table of Contents Kawailani Intersection Improvements I PROJECT LOCATION, PURPOSE AND NEED 1.1 Project Location The proposed project would improve two closely spaced intersections on Kawailani Street - Iwalani Street and Ainaola Drive/Pohakulani Street - in Hilo, Island of Hawaii (Fig. 1-l). 1.2 Lead Agencies The Federal Highway Administration (FHWA), the Hawaii State Department of Transportation (HDOT) and the Hawaii County Department of Public Works (DPW) are serving as joint lead agencies to prepare an Environmental Assessment (EA) in compliance with federal and State of Hawaii requirements. The approving authorities for the EA are the Hawaii Division Administrator of FHWA and the Director of HDOT. All the streets involved are County roads. The project will be included in the 1998-2000 federally approved Statewide Transportation Improvement Program. 1.3 Project Purpose and Need The purpose of the project is to redesign the intersections in such a way as to maximize traffic safety and minimize peak hour traffic congestion. The project would not, and is not intended to, increase the capacity of the general roadway system that feeds the intersections, as most segments of this system operate at acceptable Levels of Service. Ainaola Drive, Kawailani Street and Iwalani Streets function as collector roads conducting most of the traffic from Hilo's upland suburb of Waiakea Uka to and from schools, workplaces and shopping areas (Fig. 1-1), including the following areas: o Downtown Hilo (via Komohana Street and Waianuenue Avenue or Ponahawai Street); o Mid -town Hilo, the Hilo International Airport, and the University of Hawaii at Hilo (via Komohana Street and Kawili Street, or via Kanoelehua Avenue (State Highway 11); o Waiakea residential and shopping districts (via Komohana Street, [walani Street, and Puainako Street). Environmental Assessment 1-1 Project Location, Purpose and Need 2000' 1000' 0 2000' 4000' SCALE: 1" = 2000' PROJECT LOCATION I 1' 1 PROJECT KAWAILANI STREET IMPROVEMENTS IWALANI TO POHAKULANI STREET DATE SOUTH HILO, HAWAII g/g/gg g 1-2 Kawailani Intersection Improvements Therefore, these roads exhibit high peak hour traffic counts relative to other County roads in Hilo and are often congested during AM and/or PM peak hours. The subject intersections are unsignalized and separated by 125 m (400 ft.). The Kawailani Street/Iwalani Street intersection is a right-angle, four-way intersection, with stop signs on the minor road, Iwalani Street. Ainaola Drive intersects Kawailani Street at an acute angle and creates essentially a five -leg intersection involving Pohakulani Street as well. Ainaola Drive traffic must stop to turn left and yield on right turns. Pohakulani Street has stop signs. The less than optimal geometry and spacing of these intersections have led to greater than normal accident rates. A report on problem intersections in Hilo for the years 1991-1993 conducted by the Hawaii County Department of Public Works (Towill 1994) determined that among County road intersections in Hilo, the Kawailani-Iwalani Street intersection ranked high in accidents and met warrants for traffic signal installation. Although the other intersection was not covered in the report, it is well-known that traffic merging from Ainaola Drive onto Kawailani Street is a major contributor to accidents at both this intersection and at Iwalani Street as well. Environmental Assessment t -j Project Location, Purpose and Need Kawailani Intersection Improvements 2 DESCRIPTION OF ALTERNATIVES The County of Hawaii considered several alternative approaches to address the project's purpose and need. Section 2.1 describes the alternatives that were advanced and are the subject of this EA. Section 2.2 discusses the No Build Alternative. Section 2.3 describes several initial alternatives that were studied and found unacceptable for various reasons and thus withdrawn from further consideration. 2.1 Build Alternatives: Description. Cost and Schedule The Build Alternatives consist of four designs: 1A, IB, 2A and 2B (Figs. 2 -la - 2-1d). Each satisfies the project's purpose and need of redesigning the intersections in such a way as to maximize traffic safety and minimize peak hour traffic congestion. They are basically combinations of two alternative designs for Kawailani Street with two alternative designs for the Pohakulani Street intersection. Common to all Build Alternatives are the following: Traffic Signals: Signalization of the intersections of Ainaola Drive and lwalani The major differences between the Alternatives can be seen by comparing variants 1 vs 2 and "A" vs "B" (see Fig 2-1): Variant "A" and "B" differ subtly in their treatment of turning lanes at the two major intersections; these differences are best appreciated by viewing Fig. 2-1; most obvious are the use of narrow traffic islands in "A", and the provision of double left -turn lanes at Kawailani St. westbound at Ainaola Dr. in "B", which satisfies peak PM demand by commuters returning to Waiakea Uka. Variant "1" would realign the southern portion of Pohakulani St. 110 m (360 ft.) to the south; Variant "2" would cul-de-sac the former intersection of Pohakulani St. and Ainaola Dr., and provide a new access way to Ainaola Dr. through two vacant lots. Environmental Assessment 2-1 Alternatives Street with Kawailani Street. Lanes: Provision of additional through and turn lanes on Kawailani Street between near Kaneolani Street and Kuhilani Street (a distance of 370 in [1,200 ft.]), and on Ainaola Drive within 92 in (300 ft.) of its intersection with Kawailani Street. Full opposed left -turn lanes on Kawailani Street at both intersections. Design Standards: Travel lanes 3.4 in (11.0 ft.) in width, a paved shoulder 1.5 in (5.0 ft.) in width, and paved swales 1.5 in (5.0 ft.) in width (Fig. 2-2). Accessory Features: Replacement and upgrade of street lighting and drainage structures in conformance with federal and County standards. Schedule: With necessary approvals, the project would begin construction in 2000 and would last approximately 1 year. The major differences between the Alternatives can be seen by comparing variants 1 vs 2 and "A" vs "B" (see Fig 2-1): Variant "A" and "B" differ subtly in their treatment of turning lanes at the two major intersections; these differences are best appreciated by viewing Fig. 2-1; most obvious are the use of narrow traffic islands in "A", and the provision of double left -turn lanes at Kawailani St. westbound at Ainaola Dr. in "B", which satisfies peak PM demand by commuters returning to Waiakea Uka. Variant "1" would realign the southern portion of Pohakulani St. 110 m (360 ft.) to the south; Variant "2" would cul-de-sac the former intersection of Pohakulani St. and Ainaola Dr., and provide a new access way to Ainaola Dr. through two vacant lots. Environmental Assessment 2-1 Alternatives i T I 4- IWALANI STREET 1 hlw 3 I I. I-- i 1 II D �.. -117 C D r rn 0 :I e a �w� N Ci f I. C ik if . P 1 I POHAKULAM STREET I 11 I )' J hi I gym°. i 1. a h1., I� I i SIFJj a�t��_ i T 4- IWALANI STREET hlw 3 I I. I-- i 1 II D �.. -117 C D r rn 0 :I e a �w� N Ci f I. C ik if . � I^ . 5 1 i J 00. � 11 POHAKULAN STREET � I I i Ii !I I 11111 yr g� h 11 o :Nl YY4 n I' •0S1 ,591. rZ o(A D IWALANI STREET .Z7 I �L. Z � N a� T II Fn JD/ rD y Z N O ^ 0 O o n o 0 D r ; m i i N m N O a � j M m :� N s• C O a v \ Mei ' ♦ .f � J \ , N N } { 4 V1 AKL& 1 S L I I I. m d � i I I IN I � I rr .OSI .SBI - _ji t Ofq L =) 1.5 Dm NVALANI STREET o D P ; m mfir' ii D 0 o Y r _ � o m _ N O i S, �.L m N c, 0 0 1F N L U n A I 6 ). ' J i 9q I f \ 1 I A y 1 oN 1 -- — POHAKULANI STREET \ 14%41 it { .z. i ,a II it f•.1 Y ,k i IgA1' Irl I�t^Y D ori f'E,yti4 'I' o r I, D i � � I asl s91 o u)D I " , z-�}i. " . '� ? �' • ` IWALANI STREET m om �! Z33 o N n D F9 'DO Z o O O n O m D o If C o - k Z O � F I ! N I C .Z7 m q N O T 0 I ,i N i I D 3 o O nO U vm) _� _ ti CONSTRUCTION EASEMENT OR SLOPE EASEMENT T O o mo 3 ^' V = O Ov 01 3 0pO D 4 Z= m O N SMO Z 0;0 z �Zp �^ ; �D W U D m I I I _ ; w I �m 3 I rh A � I O 19 � � I -N n I �m� P Sz" D r I h ry ow I x;0 m DEl -K: 0 z O CI) z m I �^ N J < w 3 -0 Dm n i� O �� D �z Dec m z 0 O 0=z, Z Z zm0 o Cm m D O N O r IN I IV 0 O c S m > z O ., 3 yo in 3 W m rrrl D I ro ai m r r l D 3 CONSTRUCTION EASEMENT OR N N I <�ao D Ln D= >000 SLOPE EASEMENT \ A p Fl C) LD N _ N O r I (f) Fri Kawailani Intersection Improvements Table 2-1 compares the Alternatives on the basis of cost and right-of-way take. Table 2-1 Comparison of Costs & Right -of -Way Take for Build Alternatives Alternative Construction][Acquisition Cost ight of Way (ha/ac.)IkCost t of Total Cost IA $2.12M 0.32/0.79 $0.41M $2.53M 1B $2.28M 0.42/1.03 $0.18M $2.46M 2A $2.24M 0.53/1.31 $0.23M $2.47M 213 $2.42M 0.61/1.52 $0.27M $2.69M Note: Properties affected by right-of-way take are listed in Appendix 5. All four Build Alternatives and the No Build Alternative are under consideration at this time. The lead agencies will not select the preferred alternative until after consideration of public and agency comments on the information contained in the EA. 2.2 The No -Build Alternative The No -Build Alternative is the baseline for comparing traffic circulation and the impacts to the social and physical environment. The No -Build Alternative does not address current and future deficiencies in traffic safety and congestion at the subject intersections. However, by definition the No -Build Alternative also avoids environmental impacts associated construction - phase and permanent impacts to noise, air quality levels, and socioeconomic values. 2.3 Alternatives Evaluated and Withdrawn from Further Consideration In addition to the alternatives that were advanced and are described below, several road realignments were considered (see Fig. 1-1). In one, Ainaola Drive would be realigned to connect with Ehehene Place, which currently ends in a cul-de-sac. This would lengthen the spacing of the intersections of Ainaola Drive and Iwalani Street with Kawailani Street 125 in (400 ft.). However, it would have involved the direct taking of at least three homes and disruption to the other homes on Ehehene Street. Also considered was a cul-de-sac at the intersection of Pohakulani Street at Ainaola Drive (as in Alternatives 2A/2B) and building a new block -long road east towards Iwalani Street. However, even the least disruptive location of such a road would have resulted in direct taking of two homes. Because the Build Alternatives in Section 2.1 could accomplish the project's purpose and need without this level of community disruption, the other alternatives were withdrawn from further consideration. Environmental Assessment 2-7 Alternatives Kawailani Intersection Improvements 3 ENVIRONMENTAL SETTING AND IMPACTS This section describes the existing social, economic, cultural, and environmental conditions surrounding the proposed project along with the probable impacts of the proposed action and mitigation measures designed to reduce or eliminate adverse environmental impacts. For most categories of impact, the No Build Alternative would result in no impacts. Therefore, unless explicitly mentioned, discussion of impacts and mitigation relates to the Build Alternatives only. The island of Hawaii, home to 120,317 residents in 1990 (U.S. Bureau of the Census 1991), is largely rural. Major divisions include West Hawaii and East Hawaii. West Hawaii's dry climate and calm ocean waters support a major tourism industry in the Kona and Kohala districts. East Hawaii has an economy based on agriculture and the business and government functions headquartered in Hilo, the major city on the island. The project would take place within the city of Hilo (Fig. 1-1), which encloses about 50 square km (20 square mi.). For purposes of the environmental analysis in this document, the project site is defined as all property enclosed by a circle with a radius of 200 in (about 650 feet) centered on the Ainaola Drive/Kawailani Street intersection. The project site includes all areas potentially affected by the physical characteristics of the road: pavement, noise, runoff, carbon monoxide gas, etc. Surrounding the project site is a larger area bounded by State Highway 1 l on the east, Komohana Street and Kupulau Street on the west, and portions of Kawailani Street and Puainako Street on the north (see Fig. 1-1). Residents of this area frequently traverse the subject intersections and would thus be affected and served by the proposed improvements. This larger unit will be referred to in the EA as the project area. Because the most noticeable impacts are those related to traffic safety and congestion, and discussion of related other impacts benefits from an understanding of changes in traffic patterns, traffic impacts are presented first in Section 3.1. This is followed by discussions of the physical environment (Section 3.2), the Biological Environment (3.3), the Socioeconomic and Cultural Environment (Section 3.4), and impacts that can result from Construction (Section 3.5). The permits and approvals required for the project are listed by granting agency in Section 3.6. Environmental Assessment 3-1 Environmental Setting and Impacts Kawailani Intersection Improvements 3.1 Motorized Vehicle Transportation Patterns and Traffic afety Introduction Traffic engineers use several methods to measure the amount of traffic on a road and the efficiency with which road segments and intersections handle that traffic. Average Daily Traffic (ADT) is simply a measure of the number of motor vehicles that pass a given road segment on an average day. Peak Hour Traffic Volume measures the vehicles that pass a point or perform a turning movement during the busiest hour in terms of traffic for both the morning (AM) and afternoon (PM). Level of Service (LOS) can be used to rate signalized and unsignalized intersections. LOS is determined by comparing the amount of traffic using a roadway and the amount that the road is designed to carry (its capacity). LOS has values between A (Free Flow, when traffic Flows without congestion) and F (Forced Flow, when traffic must frequently come to a stop). LOS A, B, and C are considered acceptable. LOS D is considered a "desirable minimum" operating level of service. LOS E is an undesirable condition, and "F" is unacceptable. Current traffic data for the road segments and intersections were collected in late 1997 and early 1998. This data set was also used as the basis for future traffic projections, which were generated by a traffic engineer through modeling procedures based on the Highway Capacity Manual (Transportation Research Board 1994). The reader is referred to Appendix 1 for the full traffic assessment. Traffic volumes for the major project site roadways and ratings at the two subject intersections for the year 2018 were modeled for all Build Alternative and the No -Build Alternative (refer to Section 2 for discussion of Alternatives). The goals were to determine the overall effect of the project on future traffic patterns and to provide data for designing road features such as turning lanes and traffic signals. 3.1.1 Peak Hour Traffic Volumes and Level of Service The Level of Service for each movement of the two major intersections at the AM and PM peak hour, for 1998 and the year 2018 under both the No Build and all Build Alternatives, is depicted in Table 3-1. Currently, most turning movements operate at LOS E or F in the AM or PM peak hours. Environmental Assessment 3-2 Environmental Setting and Impacts Kawailani Intersection Improvements Regional traffic is forecasted to rise substantially in Hilo as a result of growth in both population and tourism (HDOT 1998). Accordingly, as illustrated by Table 3-1, peak hour traffic Level of Service on Kawailani Street and Ainaola Drive will also decline without improvements. (The reader is referred to Appendix 1 for detailed maps of traffic volumes). Table 3-1 Current and future Level of Service at Mainr Prniprt intarcprttnnc Source: Appendix L Multiple LOS is listed (thru lanelleft lane)where separate lanes will be provided and LOS differs between them. The major movement of such pairs is bolded. Without any traffic signal improvements, peak AM volumes are forecasted to rise between about l0 and 30 percent, depending on the location. This will produce declining Levels of Service, which will be particularly bad for the minor approaches at intersections (Table 3-I) . For example, most approaches at the Iwalani Street/Kawailani Street intersection at peak hours will be at LOS F (Unacceptable). Environmental Assessment 3-3 Environmental Setting and Impacts Year/Alternative Roadway Intersections 1998/Present 2018 2018 2018 Without Build IA/2A Build IB/2B Project AM I PM AM PM AM PM AM PM Iwalani St. Kawailani St. N -bound F E F F C B D C E -bound B B C B B/C B/C A/C B/C S -bound F F F F B B C/A C/A W -bound A A B A B/C B C B/C Ainaola Dr./ Kawailani St. N -bound E F F F B/C B/A C/A C/A E -bound A A A A B/C C B/C B/C S -bound F F F F C B C C W -bound B C B F A/B A/C B/C A/B Source: Appendix L Multiple LOS is listed (thru lanelleft lane)where separate lanes will be provided and LOS differs between them. The major movement of such pairs is bolded. Without any traffic signal improvements, peak AM volumes are forecasted to rise between about l0 and 30 percent, depending on the location. This will produce declining Levels of Service, which will be particularly bad for the minor approaches at intersections (Table 3-I) . For example, most approaches at the Iwalani Street/Kawailani Street intersection at peak hours will be at LOS F (Unacceptable). Environmental Assessment 3-3 Environmental Setting and Impacts Kawailani Intersection Improvements With improvements, regardless of the Alternative, peak hour traffic also rises, although the traffic model predicts some variation in total volumes and turning movements.' However, Level of Service in Alternatives IA/2A (Variant A) differ to some degree from 1B/2B (Variant B). For example, right -turn movements at the AM peak perform with a slightly better LOS with Variant A as opposed to B. Conversely, east -bound traffic on Kawailani Street in the PM peak has slightly better LOS with Variant B. In conclusion, the selection of any Build Alternative would lead to adequate or better Levels of Service for all movements of the two project intersections at both the AM and PM peak hours. The selection of the No Build Alternative would lead to unacceptable Levels of Service for most movements of both intersections. 3.1.2 Current and Future Safety Conditions As mentioned in Section 1.3, the less than optimal geometry and spacing of these unsignalized intersections have led to greater than normal accident rates. A report on problem intersections in Hilo for the calendar years 1991-1993 conducted by the Hawaii County Department of Public Works (Towill 1994) determined that among County road intersections in Hilo, the Kawailani-Iwalani Street intersection ranked sixth in number of accidents (14), fourth in injury accidents (5), third in accident rate per 24-hour volume count (0.000785), and second in accidents per peak hour volume (0.00919). The intersection met four warrants for traffic signal installation. Although the other intersection was not covered in the report, it is well- known that traffic merging from Ainaola Drive onto Kawailani Street is a major contributor to accidents at both this intersection and at Iwalani Street as well. Under the No Build Alternative, traffic safety conditions (as measured in accidents, injuries, and fatalities) can be expected to worsen in the future. Either Build Alternative would in all likelihood reduce accidents substantially, as is normally the case when unsafe intersections are signalized. Any Build Alternative would result in safer overall intersections. Although no major differences with regard to safety exists among the Build Alternatives, Variant 2 lengthens (and thus improves) the separation of the now closely - spaced intersections of Kawailani Street and Pohakulani Street with Ainaola Drive by 110 in (360 ft.). In terms of level of Service, there is no difference with respect to Variant I or 2, which is exclusively concerned with the treatment of the minor intersection of the south segment of Pohakulani Street with Ainaola Drive. Therefore, the important comparison is between IA -2A and IB -2B. Environmental Assessment 3-4 Environmental Setting and Impacts Kawailani Intersection Improvements 3.2 Physical Environment 3.2. l Geology and Hazards Existing Environment The island of Hawaii, youngest and largest of the Hawaiian chain, formed from the coalescence of five volcanoes during the last million years. Hilo lies just on the Mauna Loa side of the divide between lavas from Mauna Kea, which has not erupted for 10,000 years, and Mauna Loa, which is still active. The project site is located at an elevation of approximately 91 m (300 ft.) above mean sea level. The natural surface consists of an extremely stony soil that overlies lava flows from early Holocene eruptions (ca. 9,000 ka) of the Northeast Rift Zone of Mauna Loa (Wolfe and Morris 1996; U.S. Soil Conservation Service 1973). The surface also has variable quantities of imported soil. Slopes range from 2 to 10 degrees, and local relief across this generally uniform slope is minor. No known lava tube or other caves pass under or near the project site. The surface is highly permeable and runoff is slow, leading to low erosion hazard. The engineering properties of the soils present are reasonably adaptable to road construction (Cross -Reference: Section 3.4.6: Agricultural Land and Soils). This project (as all development in Hilo) would be subject to volcanic hazard, particularly lava inundation. According to the United States Geological Survey (USGS) hazard classifications, the entire project area is contained in Lava Flow Hazard Zone 3, on a scale of ascending risk 9 to 1. Zone 3 is considered "less hazardous than [Z]one 2 [which is adjacent to and downslope of active risk zones] because of greater distance from recently active vents and/or because the topography makes it less likely that flows will cover these areas" (Heliker 1990:23). According to the USGS, the Northeast Rift Zone of Mauna Loa has erupted many times in the last century, sending flows towards Hilo in the years 1880, 1899, 1935, and 1942. A 22 -day eruption in 1984 again threatened Hilo, approaching within 10 km (6 mi.) of the Kaumana neighborhood before halting. The 1881 lava flows penetrated the area now occupied by the City of Hilo, but did not approach closer than 2.4 km (1.5 mi.) of the subject intersections. In terms of seismic risk, the entire Island of Hawaii is rated Zone 4 Seismic Probability Rating (Uniform Building Code, Appendix Chapter 25, Section 2518). Zone 4 areas are at risk from major earthquake damage, especially to structures that are poorly designed or built. Partly owing to the lack of unconsolidated sediments in the local substrate, the several earthquakes of Richter magnitude 6.0 or greater that have occurred in Hilo since 1950 have caused little damage to well -engineered roads, bridges or other roadway structures. Environmental Assessment 3-5 Environmental Setting and Impacts Kawailani Intersection Improvements Impacts and Proposed Mitigation Measures Any roadway that serves Hilo south of the Wailuku River is subject to the hazard of lava flows. There are no practical measures to avoid this impact. In the event of a volcanic emergency that required evacuation of Waiakea Uka, the intersection improvements would prove valuable in allowing efficient escape. 3.2.2 Hydrology. Floodplain and Water Ouality Existing Environment Floodplain status for the project site has been determined by the Federal Emergency Management Agency (FEMA), which has mapped the area as part of the National Flood Insurance Program's Flood Insurance Rate Maps (FIRM). No floodways or floodplain are present, and the entire area is mapped as Zone X, defined as areas identified in the community flood insurance study as areas of moderate or minimal hazard from the principal source of flood in the area. Area runoff is handled via flood channels and drywells, and has water quality characteristics typical of low-density urban areas. Impacts and Mitigation Measures Road construction projects have the potential, if unmitigated, to adversely and permanently impact drainage and water quality. Construction activities such as clearing and grubbing, excavation, and paving alter the natural hydrology. Earthwork may leave soils susceptible to erosion due to rainfall runoff and can cause erosion and sediment pollution. Water quality may suffer during construction. Roadway paving increases the amount of impervious surface area, which has the potential to increase rainfall runoff. In addition, unregulated activities within a floodplain may raise flood levels or alter floodplain boundaries. Properly designed drainage structures can usually mitigate impacts to essentially zero. Government agencies regulate road construction through various permits to ensure that adverse effects are avoided or mitigated. The following permit procedures will ensure proper mitigation of drainage and water quality impacts generated by the project: County Approval of Drainage Plan. The drainage plan for the road will undergo review, revision and approval by the Hawaii County Department of Public Works (DPW) to ensure compliance with standards related to storm runoff containment. The review will require that all storm runoff is contained onsite as required in the County's Storm Drainage Standards (1970). The drainage plan will be finalized during final roadway design and is expected to consist of drywells to handle road runoff. Environmental Assessment 3-6 Environmental Setting and Impacts Kawailani Intersection Improvements NPDES. It is currently expected that a National Pollutant Discharge Elimination System permit, which would be issued by the Hawaii State Department of Health, will not be required for the project because of the relatively small land area that would be disturbed by project activities. The NPDES permit include specific and enforceable conditions to reduce sediment pollution, such as temporary silt fencing, channels, and sedimentation ponds. Regardless of the requirement for a permit, Best Management Practices for sediment reduction would be implemented. Section 3.5. l describes mitigation measures in more detail. As there are no floodplain present near the project site or affected by project activities, there would be no impacts to the natural and beneficial aspects of floodplain. 3.2.3 Climate and Air Quality Existing Environment The climate of Hilo can be described as humid and tropical. Average high temperatures in Hilo vary from approximately 26° Centigrade (C) (78° Fahrenheit [F]) in the winter to 28° C (82° F) in the summer. Temperature lows average approximately 18° C (65° F) in the winter and 21° C (70° F) in the summer. Freezing temperatures, frost and fog do not occur in the project area. Mean annual rainfall in Hilo is estimated at 330 mm (130 in.) Wind is important for its effect on dispersion or concentration of pollutants. Trade winds with an east to northeast direction occur on up to 90 percent of summer days and 50 percent of winter days. These winds are generally light, and seldom exceed an average daily speed of 16 km (10 mi.) per hour. At night, a shallow mountain drainage wind from the southwest is usually present except during episodes of strong regional wind. Trades are occasionally replaced by light and variable "kona" winds, most often in winter (UH-Manoa Dept. of Geog. 1983). Regional and local climate along with the type and amount of human activity generally dictate air quality of a given location. Federal and state air quality standards seek to limit ambient concentrations of pollutants produced by motor vehicles. These include particulate matter, sulfur dioxide (SO,), nitrogen dioxide (NO j), carbon monoxide (CO), ozone 03, and lead. These ambient air quality standards (AAQS) are specified in Section 40, Part 50 of the Code of Federal Regulations (CFR) and Chapter 11-59 of the Hawaii Administrative Rules. Each regulated air pollutant has the potential to create or exacerbate some form of adverse health effect or to produce environmental degradation when present in sufficiently high concentration for prolonged periods of time. The state and federal governments periodically monitor air quality to determine whether it meets AAQ standards. Areas that do not meet standards are termed non -attainment areas and Environmental Assessment 3-7 Environmental Setting and Impacts Kawailani Intersection Improvements are subject to Conformity Rules. These rules were issued by the Environmental Protection Agency (EPA) in response to Section 176 of the 1977 Clean Air Act. Conformity Rules prohibit any federal agency from engaging in any actions that do not conform to a state's plan to correct nonattainment situations. The entire State of Hawaii is considered to have acceptable air quality and is thus an attainment area not subject to Conformity Rules. Air quality in the project area is currently mostly affected by emissions from motor vehicles, industry and natural sources. Volcanic emissions of sulfur dioxide convert into particulate sulfate which causes a volcanic haze (vog) to blanket the area during occasional episodes when trade winds are not present. The major industrial source is oil -fired power plants which emit SO,, nitrogen oxides (NO.), and particulate matter. Motor vehicles emit CO, NOx, hydrocarbons (an ozone precursor), as well as smaller amounts of other pollutants. The State of Hawaii operates a network of air quality monitoring stations around the state. Very little data are available for the Hilo area. In general, these data indicate that concentrations are well within state and federal air quality standards. The excellent air quality in Hilo is mainly influenced by the dispersive effects of the trade winds and the isolation of the island from any outside sources of pollution. The more stringent state standards pertaining to CO are probably exceeded on occasion near high-volume intersections during periods when traffic congestion and poor dispersion conditions coincide. Impacts and Mitigation Measures The intersection improvements are not expected to generate any additional traffic in the Hilo area. Impacts to regional air quality (which is currently excellent) would probably be somewhat beneficial because of the predicted decrease in congestion and queuing. However, wherever vehicles are present - and particularly at intersections - there is the potential for what air quality specialists call microscale impacts. To evaluate the potential impact, an air quality specialist employed computerized emission and atmospheric dispersion models that estimate ambient carbon monoxide (CO) concentrations along roadways leading to and from the project. CO was selected for modeling because it is the most stable and abundant of the pollutants generated by vehicles (see Appendix 2). The main objective of the modeling study was to estimate maximum 1 -hour and 8 -hour CO concentrations for the two intersections at the present date (1997) and the future (2018) for all alternatives. Maximum concentrations were calculated for both morning and afternoon peak hours, using the MOBILSA computer model. The model incorporates terms for traffic volume, average speed, vehicle mix (i.e., different types of motor vehicles and engines), cold/hot start modes (i.e., whether most vehicles will be "warmed up" and burning fuel Environmental Assessment 3-8 Environmental Setting and Impacts Kawailani Intersection Improvements efficiently), and other factors. After emissions were calculated, a dispersion model (CAL3QHC) was used to determine how CO would disperse away from the intersection. "Worst case" meteorological conditions (wind speeds of less than 1 meter/second, blowing towards the most sensitive areas) were used in order to arrive at a conservative estimate. Tables 3-2 and 3-3 provide the results of the analysis. Table 3-2 Estimated Worst -Case 1 -Hour Carbon Monoxide Concentrations (milligrams per cubic meter) Source: Appendix 2 Notes: Concentrations are estimated for areas 3 in away from traveled portion of roadway at 1.8 in height. Hawaii State Ambient Air Quality Standard for CO: 10 Federal Ambient Air Quality Standard for CO: 40 As shown in Table 3-2, worst-case carbon monoxide levels at peak hours do not exceed federal or State of Hawaii standards. The 2018 No -Build Alternative would find CO levels increasing above State standards at the PM peak hour. CO levels would remain below standards for All Build Alternatives, and would in some cases actually improve relative to current levels. This is because the project would provide better Level of Service (see Section 3.1) Table 3-3 supplies the worst-case 8 -hour concentrations for these intersections. No exceedances occur under any Build Alternative, and CO levels would remain about the same as now. Again, the No Build Alternative would produce CO levels in excess of state standards. Environmental Assessment 3-9 Environmental Setting and Impacts Year/Alternative Roadway Intersections 1997/Present 2018 2018 2018 with Without Build IA/2A Build 1B/2B Kawailani St. Project AM PM AM PM AM PM AM PM Iwalani St. 5.0 6.0 6.6 6.0 1 7.0 5.9 6.4 5.8 Ainaola Dr. - 6.9 7.5 9.3 13.76.4 5.4 7.5 6.7 Pohakulani St Source: Appendix 2 Notes: Concentrations are estimated for areas 3 in away from traveled portion of roadway at 1.8 in height. Hawaii State Ambient Air Quality Standard for CO: 10 Federal Ambient Air Quality Standard for CO: 40 As shown in Table 3-2, worst-case carbon monoxide levels at peak hours do not exceed federal or State of Hawaii standards. The 2018 No -Build Alternative would find CO levels increasing above State standards at the PM peak hour. CO levels would remain below standards for All Build Alternatives, and would in some cases actually improve relative to current levels. This is because the project would provide better Level of Service (see Section 3.1) Table 3-3 supplies the worst-case 8 -hour concentrations for these intersections. No exceedances occur under any Build Alternative, and CO levels would remain about the same as now. Again, the No Build Alternative would produce CO levels in excess of state standards. Environmental Assessment 3-9 Environmental Setting and Impacts Kawailani Intersection Improvements Table 3-3 Estimated Worst -Case 8 -Hour Carbon Monoxide Concentrations (milligrams per cubic meter) Source: Appendix 2 Notes: Concentrations are estimated for areas 3 in away from traveled portion of roadway at 1.8 m height. Hawaii State Ambient Air Quality Standard for CO: 5 Federal Ambient Air Quality Standard for CO: 10 Mitigation Measures In essence, the Build Alternative would improve air quality. No exceedance of State of Hawaii or federal air quality standards would occur, and therefore no mitigation is necessary. 3.2.4 Noise Levels Existing Environment A study of the acoustic environment of the project corridor along with estimates of the effects of all alternatives was conducted for this EA (Appendix 3). Noise may be defined as unwanted sound. Evaluation of noise requires a consideration of loudness at various pitches. Loudness is measured in units called decibels (dB). Since the human ear does not perceive all pitches or frequencies equally, noise levels are adjusted (or weighted) to correspond to human hearing. This adjustment is known as the A -weighted scale, abbreviated dBA. The specific sound level descriptor used in this study is the hourly energy equivalent sound level (Lq) in decibels (dB), which considers the combined effects of all noises near and far and includes background noise and noise fluctuation. Noise levels over 70 decibels are considered unpleasant by most individuals; levels under 50 decibels are generally perceived as acceptably quiet. Environmental Assessment 3-10 Environmental Setting and Impacts Year/Alternative Roadway Intersections with 1997/Present 2018 2018 2018 Kawailani St. Without Build IA/2A Build IB/2B Project Iwalani St. 3.0 3.3 3.5 3.2 Ainaola Dr. - 3.8 6.8 3.2 3.8 Pohakulani St Source: Appendix 2 Notes: Concentrations are estimated for areas 3 in away from traveled portion of roadway at 1.8 m height. Hawaii State Ambient Air Quality Standard for CO: 5 Federal Ambient Air Quality Standard for CO: 10 Mitigation Measures In essence, the Build Alternative would improve air quality. No exceedance of State of Hawaii or federal air quality standards would occur, and therefore no mitigation is necessary. 3.2.4 Noise Levels Existing Environment A study of the acoustic environment of the project corridor along with estimates of the effects of all alternatives was conducted for this EA (Appendix 3). Noise may be defined as unwanted sound. Evaluation of noise requires a consideration of loudness at various pitches. Loudness is measured in units called decibels (dB). Since the human ear does not perceive all pitches or frequencies equally, noise levels are adjusted (or weighted) to correspond to human hearing. This adjustment is known as the A -weighted scale, abbreviated dBA. The specific sound level descriptor used in this study is the hourly energy equivalent sound level (Lq) in decibels (dB), which considers the combined effects of all noises near and far and includes background noise and noise fluctuation. Noise levels over 70 decibels are considered unpleasant by most individuals; levels under 50 decibels are generally perceived as acceptably quiet. Environmental Assessment 3-10 Environmental Setting and Impacts Kawailani Intersection Improvements To assess existing noise and the potential for impacts, existing traffic and background ambient A -weighted noise levels were measured at various locations near the intersections (Fig. 3-1). Measurements determined that existing traffic noise levels varied between 58 and 65 L,q at typical house setback distances from the roadway centerline (i.e., 16-32 in [50-100 ft. 1). Local traffic and household noises tend to be the dominant noise sources. The acoustical study used existing traffic noise measurements to develop and calibrate a model that projected future traffic noise levels associated with the proposed project under the No - Build and various improvement alternatives. The FHWA Traffic Noise Prediction Model was the primary method. The model incorporates parameters for terrain, ground cover, and local shielding conditions. The agreement between measured and predicted traffic noise levels is illustrated in Table 3-4. The agreement confirmed that the traffic model could consistently and accurately predict future traffic noise levels. Table 3-4 Traffic Noise Measurements and Model Predictions. Selected Sites LOCATION Measured L Predicted L LOCATION Measured L Predicted L A: 11 m (35 ft.) E: 15 (50 ft.) from from Kawailani St. 62.4 62.7 Ehehene PI. 44.0 41.6 centerline; centerline; Time: 07:30-08:00 Time: 12:00-13:00 D: 11 in (35 ft.) I: 11 m (35 ft.) from Kuhilani St. 56.5 55.2 from Ainaola Dr. 64.9 65.3 centerline; centerline; Time: 10:45-11:45 Time: 10:30-10:53 Source: Appendix 3, Table 1; See Fig. 3-1 of EA for letter symbol locations. Analysis of airphotos and project plans determined that fifteen noise -sensitive properties - each a single-family residence - were sufficiently close to the 66 L�q sound contour that they might potentially experience noise impacts. Detailed study of future noise levels under the Build and No Build Alternatives were undertaken at these locations. Environmental Assessment 3-11 Environmental Setting and Impacts NORTH GRAPHIC SCALE: ® SCALE: 1000' 500' 0 1000' 2000' 1" = 1000' TLE NOISE MEASUREMENT SITES 3.1 NFi UJLC ' KAWAILANI STREET IMPROVEMENTS IWALANI TO POHAKULANI STREET UA IL SOUTH HILO, HAWAII 1 9/8/98 GH -NOSE c"y 3-17 Kawailani Intersection Improvements Impacts and Mitigation Measures In residential/business districts such as the project site, two measures are used to determine whether noise impacts have occurred and noise mitigation measures should be considered. One is whether the FHWA noise abatement criterion of 67 Lq for residences, schools, churches, and similar land uses (U.S. DOT Policy and Procedure Memorandum 90-2) is exceeded or "approached," which is defined in Hawaii as 66 Lq or greater. The second measure is the State DOT policy that defines any difference of 15 dB or greater between existing and predicted noise levels at the project year of 2018 as a "substantial" increase. If either condition is met, a noise impact is considered to have occurred. When noise impacts occur, reasonable and feasible mitigation measures must be considered. A noise mitigation measure is considered feasible and reasonable if it accomplishes a substantial noise reduction (at least 5 dBA) while meeting constraints of cost, safety, drainage, access, maintenance, viewplane preservation, etc. According to current State policy, the price of mitigation should not exceed $35,000 per affected residence. It is also important to weigh the overall magnitude of noise impacts and the contribution of other noise sources, as well as the benefit to all nearby residences (not just those defined as impacted by noise increases above criteria), when judging if a mitigation measure is "reasonable". Furthermore, State policy stresses that the opinion of impacted residents will be a major consideration in determining the reasonableness of the noise abatement measures. Finally, it is recognized that it is the policy of Hawaii County to discourage walls higher than 1.8 meters (6.0 ft) in order to preserve viewplanes. According to Section 25-4-43 of the Hawaii County Code, any proposed wall higher than 1.8 meters (6.0 ft) requires a building permit and is subject to 9 in (30 ft) setback requirements. Exceptions to such setback require variance applications on a property -by -property basis. Impacts of the No -Build Alternative According to the acoustic analysis, although noise would increase at all locations in the project site by 0.8-2.7 dB by the project year 2018, none of the noise -sensitive properties would experience noise increases exceeding 15 dB or absolute levels above 66 L., at either the AM or PM peak hours. Therefore, according to state and federal policy, no noise impacts of a magnitude large enough to necessitate consideration of mitigation measures would occur. Impacts of the Build Alternatives By contrast, all Build Alternatives would cause noise impacts for at least 4 residences (Fig. 3- 2a -b; Table 3-5). Little difference exists among Alternatives: IA would impact 4 residences; 2A would impact 5; 1B and 2B would each impact 6 residences. The magnitude of the impact is in all cases small, with the maximum predicted noise level at any receptor less than 68.0 L,. Environmental Assessment 3-13 Environmental Setting and Impacts a)zi >0! Fn- mi —wz m >>O r 4� Eli M 65 M C) ct cu m m mo� 6z: m 0 ZOO =O j3: E) z m I O F5 M D > 0 r5 ----,-,fWALAN STREET f m >m 4� ai>z0 C) ct z (j) mm o O F5 M D > 0 r5 ----,-,fWALAN STREET f m >m ai>z0 C) ct z (j) mm o CO 0 > m m z 0 T 0 m > Cf) m z wo Ct K X0 8) z :() Cf) ;p MIM 3 M o z CD uD 0 > n 0 z 0 z M > 0 CiD m 0 z O F5 M D > 0 r5 ----,-,fWALAN STREET f � fm+ULA9STRE g § mm \'\ ;§ f § \m bj from Ij o,] �.§ 0z z�Q j' \?\< \ z .m mm - « «-y*am SEE ,... >. . | / O | m °.� /§ 7 | 2 20 . m \ 7 m � �0 /\ Gz ` \ 2 Fil 2 § § $2 mm \ _ Fn cn S § § ®/ k j 7 60 r § § X I \ \ � \\ 0 Kawailani Intersection Improvements Table 3-5 Noise Impacts and Mitisation PROP. ID EXISTING (1997) Lq 2018 LeqBUILD (by Alternative) lA 2A 1B 2B Sound Reduction Achieved Through Barriers (dBA) 1 63.8 n/i n/i 66.2 66.2 1A/2A: n/i 1B/2B: 5.0 2 64.1 66.1 66.1 66.6 66.6 IA/2A: 5.4 1B/2B:5.8 5/6* 64.2 67.0 67.0 67.8 67.8 IA/2A: 5.5 1B/2B:5.6 7 64.2 66.5 66.5 67.2 67.1 1A/2A: 5.0 1B/2B:5.0 11 63.0 66.2 67.0 67.2 67.1 1A/2A: 6.0 1B/2B:6.3 12 63.6 n/i 66.8 66.8 67.9 lA/2A: 5.0 1B/213:5.0 Source: Appendix 3, Tables 9A-13. Notes: For Property ID locations and noise barrier specifications and locations, refer to Figure 3-2; Existing noise levels, impacts and mitigation are listed for AM peak hour, which has greater impacts than PM peak hour at all locations under all alternatives in all cases. n/i = No Impact; ' is one residence. Modeling of the potential sound reduction that could be provided by noise mitigation barriers was undertaken as part of the acoustic analysis. As shown in Table 3-5, it was determined that a series of barriers with heights between 1.7 m and 2.1 m (5.5 to 7.0 ft. - See Figs. 3 -2a -b for location and heights) could achieve sound reductions greater than 5.0 dBA at all impacted residences under any Alternative. The cost of such walls are shown below in Table 3-6. Table 3-6 Noise Miti ation Barrier Cost Receptor/ 1 2 5/6 7 11 12 Alternative WALL HT. 6.5 ft. 6 ft. 6 ft. 7 ft. 5.5 ft. 7 ft. Alternatives 1B, 2B All All All All 1B, 2A, with Noise 2B Impacts WALL COST ($) j 23,000 j 24,725 j 26,875 j 22,800 j 37,310 j 33,600 Sources: Wall height: Appendix 3, Table 10. Notes: calculations based on square feet of noise absorbing surface ® approx. $215 linear foot (based on (-foot wall); u/i = no impact; for [wise barrier heights and locations, refer to Figures 3 -2a -b. Environmental Assessment 3-16 Environmental Setting and Impacts Kawailani Intersection Improvements On the basis of cost exceeding $35,000 per residence, noise mitigation measures do not appear to be reasonable for the home identified as receptor 11 under any Build Alternative. For all receptors, the walls would detract to some degree from the visual quality of the neighborhood, in which yards are often not separated by fences from each other or the roads and provide pleasant, continuous landscapes of lawns and tropical ornamental vegetation. This would be particularly true for the 2.1 m (7.0 ft.) high walls. However, the visual impact would be minor in relation to the marked benefit of noise reduction. Weighing the substantial noise reduction and cost below the threshold of $35,000 per residence, the use of mitigation measures would appear both reasonable and feasible for the homes identified as receptors 1, 2, 5/6, 7 and 12 for all Build Alternatives. A final decision on the installation of these mitigation measures will be made upon completion of project design and the public involvement process. If during final design conditions substantially change in such a way as to render mitigation unreasonable or infeasible, these mitigation measures may be modified.' 3.3 Biological Environment and Wetlands The County of Hawaii consulted the U.S. Fish and Wildlife Service (USF&WS) for information on the distribution of rare, endangered or threatened plants and animals and for advice on mitigation of impacts (see Appendix 4 for coordination letter). The project area is completely urbanized and does not contain any natural vegetation, streams, wetlands or aquatic sites, or other areas that might be of concern for biological impacts. Accordingly, the USF&WS concluded in a letter of 26 June 1998 that: "...no threatened or endangered species are known to occur in the vicinity of the proposed intersection improvements and no significant adverse impacts to fish and wildlife resources are expected to result from the proposed project" (see Appendix 1 for full text of consultation letter). ` Subsequent to the noise study, traffic volumes were recalculated. The effect of this change on future noise levels and potential mitigation measures is minor but has not been precisely modeled. The acoustic environment will be modeled again before construction, when design is finalized and detailed topography is available. Mitigation measures will be reconsidered in light of the information from that study, and they may thus differ from those proposed here. Environmental Assessment 3-17 Environmental Setting and impacts Kawailani Intersection Improvements 3.4 Socioeconomic 3.4.1 Community Identity and Right -of -Way Acquisition Existing Environment and Impacts The intersections of the project site are in the upper part of the Waiakea neighborhood of Hilo and are at the boundary of Waiakea Uka (Fig. 3-3). The project area encompasses this latter area, which was formerly a somewhat separate rural community with mainly small farms and sugar cane camps, but is now essentially part of suburban Hilo. The project site is a residential neighborhood with a small commercial center housing a convenience store, a video store and a gas station. Although residential subdivisions dominate land use in Waiakea Uka, much land is still devoted to small farms and cattle ranches. No unique local government jurisdictions exist. The 1990 U.S. Census of Population provides the most recent demographic information. The census data are still reasonably accurate for Hilo in the late 1990s, although many neighborhoods in the project area have expanded in population since that time. Table 3-7 presents demographic data for the census tracts and block groups that contain the residents most directly affected by the project. The project site and project area are near the average in most measures except with somewhat higher home values, incomes and rents. Minority populations are in general distributed evenly around the island of Hawaii, and the neighborhoods affected by this project are similar to others on the island. Minority or low- income groups will not experience disproportionately high adverse impacts through construction -phase impacts, right-of-way taking, long-term noise and air quality effects, or other adverse effects. The project is not expected to adversely impact the identity or cohesion of this community. Although the widened profile will increase the "barrier effect" of Kawailani Street, traffic signals and crosswalks will promote safer use by pedestrians. The project will require acquisition of 0.32-0.61 ha (0.79-1.52 acres) of right-of-way from adjacent landowners (Appendix 4 lists all affected properties). Alternatives 2A and 2B would require taking two entire lots (both vacant of structures) for a new connector between Ainaola Drive and Pohakulani Street. Acquisition of property for right-of-way will be satisfied in conformance to the requirements of the Uniform Relocation Assistance and Real Property Acquisition Act of 1970, as amended. Environmental Assessment 3-18 Environmental Setting and Impacts TITLE KUPULAO ROAD LEGEND: CENSUS TRACT BOUNDARY aED 000000' BLOCK GROUP BOUNDARY 208.01 CENSUS TRACT NUMBER ................. B61 BLOCK GROUP m 207.02 m 1 208.01 M 862 MD209 ................. B61 KINOCLE STREET KILAUEA AVENUE CENSUS TRACTS AND BLOCK GROUPS 205 3-3 K01ECT KAWAILANI STREET IMPROVEMENTS IWALANI TO POHAKULANI STREET DATE SOUTH HILO, HAWAII 9/g/98 GR-CENSU a.g 3-19 Kawailani Intersection Improvements Table 3-7 1990 U.S. Census Data. Census Tracts/Block Gronns Trait/Unit 207.01 Lower Waiakea: Puainako to Haihai 207.01 Block Group 3 Iwalani to Puainako 207.02 Upper Waiakea: Kawailani to Ku ulau 207.02 Block Group 3 Iwalani to Komohana Hilo PERSONS 4,399 1,294 4,693 1.468 37,808 FAMILIES 1,256 359 1,263 400 9,715 HOUSEHOLDS 1,559 418 1,460 452 13,234 %FEMALE 51.0 48.1 51.5 50.7 51.2 %Low Income 6.2 4.1 6.0 4.4 14.5 ETHNIC %CAUC 16.8 15.8 20.9 21.0 26.6 %FILI 9.2 9.9 11.9 12.6 9.5 %HAWA 15.6 15.4 12.7 11.9 20.0 %JAPA 51.8 51.9 47.2 46.5 35.2 %MINORITY 84.4 84.9 81.8 82.2 75.8 AGE % < 18 22.5 26.3 32.5 25.0 27.3 %>59 27.9 21.2 11.8 14.4 19.9 %OWN-OCCU 74.6 85.6 98.9 86.7 56.7 %VACANT 1.7 0.0 2.1 2.2 5.7 SMED HOME VALUE 114,900 117,000 121,400 113,500 84,700 Swore: U.S. Cenam of Population, 1990 STPI-A. Nae: Refer to Fgure 3-3 for Census Tract boundaries. Key: ETHNIC: CAUC=Caumlan (includes Hispanic Cauaaiuu, who an included in Minority category below), FILI=Filipino, HAWA=Hawaiian; JAPA=Japanese{ RENT: MED=Med'un rem: Low income is defined as below Census Bureau Poverty threshold. Environmental Assessment 3-2U Environmental Setting and Impacts Kawailani Intersection Improvements 3.4.2 Planning Planning responsibility for the Island of Hawaii rests with the Hawaii County Planning Department and the State Land Use Commission. Hawaii County General Plan The General Plan for the County of Hawaii is a policy document expressing the broad goals and policies for the long-range development of the Island of Hawaii. The current General Plan was adopted by ordinance in 1989 (a revision is currently in early stages). The General Plan Facilities and LUPAG Maps are the map components of the General Plan that together establish the basic urban and non -urban form for areas within the planned public and cultural facilities, public utilities and safety features, and transportation corridors. The Facilities Map identifies both Kawailani Street and Ainaola Drive as Secondary Arterials proposed for improvement. Secondary arterials are defined in the General Plan as streets of considerable continuity which are primarily traffic arteries for intercommunication between or through large areas. They interconnect with and augment primary systems. The Land Use Pattern Allocation Guide (LUPAG) map is a graphic representation of the Plan's goals and policies. Land surrounding the project corridor is identified for Low Density Urban use. County Zoning County zoning for properties in the project site varies from 7,500 and 10,000 sq. ft. Residential (RS -7.5; RS -10) to commercial (CV). The proposed project is a permitted use in all these zones. State Land Use District All land in the State of Hawaii is classified into one of four land use categories -- Urban, Rural, Agricultural, or Conservation -- by the State Land Use Commission. The project site is designated Urban. The proposed project would be an identified use in this district. Impact of Project on Planning The proposed project is consistent with all planning. No rezoning, reclassification or use permits are required. Widening or realignment that involves land acquisition would require compliance with Chapter 23, Hawaii County Code, relating to Subdivision. Environmental Assessment 3-21 Environmental Setting and Impacts Kawailani Intersection Improvements 3.4.3 Land Use Existing Land Use Existing land use in the project site consists primarily of residential and commercial uses. Impacts and Mitigation Measures No adverse impacts to existing or proposed land uses would result from the project. 3.4.4 Public Services and Facilities Utilities Waterlines and utility poles and lines providing for electricity, telephone and cable television service are present at the project site. Waterlines would not be affected, but a number of utility poles would require relocation to the edge of the new right-of-way. Electricity for street lights and signal lights at intersections will be available from existing power lines at the intersections. Police, Fire and Emergency The Waiakea Fire Station is located approximately 80 m (250 ft.) east of the Iwalani Street intersection. Widening would require taking of about 3 m (10 ft.) in front of the station. The Hawaii County Fire Department has been notified of this project and invited to comment on the Environmental Assessment. In general, police, fire and emergency medical services will benefit from the project because it will reduce accidents and congestion at the intersection. Other Services No recreational facilities are located in or near the project corridor, and no impact to recreation would occur. School traffic, including buses and parents taking children to and from school, represents a substantial portion of use at AM and PM peak hours. These users would benefit from increased safety and decreased congestion. Environmental Assessment 3-22 Environmental Setting and Impacts Kawailani Intersection Improvements 3.4.5 Historic Sites/Archaeological Resources Section 106 of the National Historic Preservation Act provides protection for historic sites. This law designates the State Historic Preservation Officer (SHPO) in each state as the entity responsible for coordination and consultation on historic sites. Accordingly, the SHPO was consulted. All land in the project site has been completely altered by construction or clearing within the last 30 years. There are no known structures or remains dating from before this period. No historic sites appear to be present, and none are listed in the U.S. or Hawaii Registers of Historic Places in or near the project site. The SHPO issued a letter on 13 July 1998 stating that no effects to significant historic sites would likely occur as a result of the road construction (see App. 4 for coordination letter). 3.4.6 Agricultural Land and Soils Soil on the project site is classified by the U.S. Natural Resources Conservation Service as Olaa Extremely Stony Silty Clay Loam. This soil is typically 30 cm in thickness and is underlain by a 25 cm subsoil, and then by 'a'a (clinkery) lava. The soil is rapidly permeable with slow runoff, and erosion hazard is thus slight. Areas of this soil type in the project area were formerly farmed in sugar cane and now support some pasture or diversified tree crops. The federal Farmland Protection Policy Act (FPPA) seeks to conserve farms and farmland by requiring assessment of a highway project's relative impact on farmland in a region, county and state. Consultation of maps of important farmland provided by the U.S. Natural Resources Conservation Service (USNRCS) determined that no lands identified as Prime, Unique, or Other Important Lands in the Agricultural Lands of Importance to the State of Hawaii (ALISH) map series are present. The project site is classified as urban and is thus not inventoried. Field inspection determined that no farms are present within the corridor. No farming operations would be adversely impacted by the project. 3.4.7 Pedestrian and Bicycle Transportation Patterns Existing Conditions No sidewalks or bicycle facilities are currently present at the project site. The Bike Plan Hawaii (HDOT 1994) serves as the guide for implementation of bikeways for the State of Hawaii. According to this plan, Kawailani Street is designated as a future proposed bike route, and Ainaola Drive is a future proposed bike lane.' Bicycle traffic is currently not monitored in ' The Hawaii State Department of Transportation defines a bike lane as "A portion of a roadway designated by striping, signing, and pavement markings for the preferential or exclusive use of bicycles." A bike Environmental Assessment 3-23 Environmental Setting and Impacts Kawailani Intersection Improvements the project area but does not appear to be substantial. Some commuting by bicyclists may occur between the project area and Waiakea High School and the University of Hawaii at Hilo, which are adjacent to each other about 1.0 km (0.6 mi.) from the project site. Both Kawailani Street and Ainaola Drive currently lack not only bike lanes, but also sidewalks or paved shoulders. The County has no plans to provide these here in the foreseeable future. Impacts and Proposed Mitigation Measures Neither Kawailani Street nor Ainaola Drive can be made sufficiently wide to accommodate separate bicycle and pedestrian facilities and allow acceptable motor vehicle Levels of Service without the severe adverse impact of taking homes. Given this constraint, along with the light pedestrian and bicycle traffic in the area and the absence of current or future planned bike lanes or sidewalks in the streets involved, separate pedestrian and bicycles facilities are not proposed. However, the project design includes provision of 1.5 m (5.0 ft.) shoulders on Kawailani Street and Ainaola Drive to be shared by pedestrians and bicyclists. 3.4.8 Secondary. Growth -Inducing and Cumulative Impacts When road construction projects create or substantially accelerate new opportunities for urban growth, secondary or induced physical and social impacts may also occur. These can include impacts to air quality, water quality, noise, open space, natural vegetation, historic sites, demands for public infrastructure, and other aspects of the environment. Because the project is not expected to generate growth, such secondary impacts would not occur. There is negligible potential for growth -induction along the project corridor because of a safety related improvement such as the proposed project. Cumulative impacts result when implementation of several project that individually have limited impacts combine to produce more severe impacts or conflicts in mitigation measures. The adverse effects of the project are very limited in severity and geographic scale. There are no projects being undertaken nearby which would combine with the Kawailani/Ainaola project to produce cumulative impacts. 3.4.9 Coastal Zone Management Act (CZMA) The purpose of the federal Coastal Zone Management Act (CZMA) of 1972 (U.S.C. 1451- 1464) is to preserve, protect, develop and where possible enhance the resources of the coastal zone. All projects with federal involvement that significantly affect areas under the control of a state's CZM Agency must undergo review for consistency with the State's approved coastal program. The entire State of Hawaii is included in the coastal zone for such purposes. The objectives of the Hawaii Coastal Zone Management Program are the following: path, by contrast, is completely separated from the roadway and is normally exclusively for bicycles. A bike route is defined as "Any street or highway so designated, for the shared use of bicycles and motor vehicles or pedestrians or both." Environmental Assessment 3-24 Environmental Setting and Impacts Kawailani Intersection Improvements Recreational Resources: Provide coastal recreational opportunities accessible to the public. Historic Resources: Protect, preserve, and where desirable, restore those natural and man-made historic and pre -historic resources in the coastal zone that are significant in Hawaiian and American history and culture. Scenic and Open Space Resources. Protect, preserve, and where desirable, restore or improve the quality of coastal scenic and open space resources. Coastal Ecosystems. Protect valuable coastal ecosystems from disruption and minimize adverse impacts on all coastal ecosystems. Economic Uses. Provide public or private facilities and improvements important to the State's economy in suitable locations. Coastal Hazards. Reduce hazard to life and property from tsunami, storm waves, stream flooding, erosion, and subsidence. Managing Development. Improve the development review process, communication, and public participation in the management of coastal resources and hazards. The Hawaii County Department of Public Works believes that the project does not impact these coastal zone resources and is consistent with the objectives of the program. This EA will be reviewed by the Hawaii State Coastal Zone Management Program for official review of its consistency. 3.5 Construction -Phase Impacts Construction of the proposed project would last approximately one year. During this period construction vehicles, power tools and heavy equipment would generate noise, traffic congestion, exhaust emissions and the potential for soil erosion. Residents and others with property directly adjacent to the improvements would be the most directly affected by construction. This group includes a total of less than 30 residences, the small commercial center with a convenience store, a video store and a gas station, the Waiakea Fire Station, and a Hawaiian Telephone -GTE building. 3.5.1 Sediments, Water Quality and Flooding Impacts Uncontrolled excess sediment from soil erosion during and after road construction can impact natural watercourses, water quality and flooding potential. Contaminants associated with heavy equipment and other sources during construction may also impact receiving stream, ocean and ground water. Environmental Assessment 3-25 Enviromnental Setting and Impacts Kawailani Intersection Improvements Proposed Mitigation Measures Depending on aspects of the project that await final design for determination, a National Pollutant Discharge Elimination System (NPDES) permit may be required for the construction phase of the project. The permit, which would be issued by the Hawaii State Department of Health, would include specific and enforceable conditions to reduce sediment pollution. Regardless of whether an NPDES permit is required, if the Build Alternative is selected, Special Contract Requirements developed as part of the construction documents will contain provisions to minimize the potential for soil erosion and off-site sediment transport. Soil erosion and sediment control standard management practices shall be implemented, as described in the Erosion and Sediment Control Guide for Hawaii (USSCS 1981). These management measures may include: o Limiting the amount of surface area graded at any given time to reduce the area subject to potential erosion; o Constructing temporary drainage ditches to divert runoff away from areas susceptible to soil erosion; o Utilizing soil erosion protective materials such as mulch or geotextiles on areas where soils have a high potential for erosion until permanent provisions such as lawns and grasses can be developed; and o Planting grass as soon as grading operations permit to minimize the amount of time soils are exposed to possible erosion. 3.5.2 Air Ouality Impacts Short-term air quality impacts would occur either directly or indirectly during project construction. Short-term impacts from fugitive dust would likely occur, and increased emissions from traffic disruption may also affect air quality during construction. State air pollution control regulations prohibit visible emissions of fugitive dust. Mitigation An effective dust control plan is necessary to mitigate construction -related impacts. Special Contract Requirements developed as part of the construction documents will specify the following elements of the plan, the final provisions of which would be approved by DOH, and which would include some or all of the following: o Watering of active work areas; o Wind screens; Environmental Assessment 3-26 Environmental Setting and Impacts Kawailani Intersection Improvements o Cleaning adjacent paved roads affected by construction; o Covering of open -bodied trucks carrying soil or rock; o Limiting area to be disturbed at any given time; o Mulching or chemically stabilizing inactive areas that have been worked; o Paving and landscaping of affected areas of the project site as soon as practical in the construction schedule; and o If prolonged dry periods occur, watering of active work areas at least twice daily. Construction vehicles and disrupted traffic due to construction activity can also produce increased exhaust emissions. To avoid this, Special Contract Requirements developed as part of the construction documents will specify that contractors will move construction equipment and workers on and off the site during off-peak traffic hours. 3.5.3 Noise Impacts Construction would result in noise from grading, blasting, compressors, vehicle and equipment engines, and other sources. Construction activities may exceed 95 decibels (dB) at the project boundary lines at times. Mitigation Special Contract Requirements developed as part of the construction documents will specify that the contractor conform with Title 11, Chapter 46, HAR (Community Noise Control). The Hawaii State Department of Health's (HDOH) Noise, Radiation and Indoor Air Quality Branch issues permits for construction activities which may generate noise. The permit is applied for during the construction phase by the contractor. HDOH will review the type of activity, location, equipment, project purpose, and timetable in order to decide upon conditions and mitigation measures. Possible measures include restriction of equipment type, maintenance requirements, restricted hours, and portable noise barriers. The precise combination of mitigation measures, if any, shall be specified by HDOH prior to construction. Environmental Assessment 3-27 Environmental Setting and Impacts 3.5.4 Traffic Coneestion Impacts Kawailani Intersection Improvements For intervals during construction, operation of construction equipment, trucks, and worker vehicles may temporarily impede traffic at the subject intersections. Mitigation Special Contract Requirements developed as part of the construction documents will specify that during the construction period: o Professional traffic control shall be utilized throughout construction o Intersections will remain open during the AM and PM peak hours, i.e., from 7:00-8:00 AM and between 4:30 - 5:30 PM. Additionally, it should be noted that noise -related construction time restrictions may also be imposed by the Hawaii State Department of Health as pan of the Construction Noise Permit (see Section 3.5.3 above). 3.5.5 Public Utilities Impacts Road construction would entail potential relocation and/or temporary removal of electricity/telephone poles and transmission lines, and water mains and distribution lines. Mitigation Special Contract Requirements developed as part of the construction documents will specify that the contractor will coordinate with utility companies to schedule disruption so as to minimize the inconvenience to utilities and their customers. Environmental Assessment 3-28 Environmental Setting and Impacts Kawailani Intersection Improvements 3.6 Required Permits and Approvals Several permits and approvals would be required to implement this project. They are listed here under their granting agencies. Permits/Approvals Currently Under Consideration: Hawaii Coastal Zone Management Program a. Coastal Zone Management Program Consistency Review Permits/Approvals Sought Prior to Construction: State Department of Health: a. National Pollutant Discharge Elimination System Permit* County Department of Public Works: a. Permits for Excavation of Public Highway, Grading, Grubbing, and Stockpiling b. Permits for Outdoor Lighting C. Permits for Electrical Work County Planning Department a. Permit for Subdivision * Denotes need for permit/approval is not yet determined. Environmental Assessment 3-29 Environmental Setting and Impacts Kawailani Intersection Improvements 4 COMMENTS AND COORDINATION 4.1 Agencies Contacted The following agencies received a letter inviting their participation in the preparation of the Environmental Assessment. Federal Agencies Pacific Islands Ecoregion U.S. Fish and Wildlife Service P.O. Box 50167. Honolulu. HI 96850 Chief, Planning and Operations Division U.S. Army Engineer District, Honolulu Ft. Shafter HI 96858-5440 State Agencies State Historic Preservation Division 33 South King Street, 6th Floor Honolulu, Hawaii 96813 Chancellor's Office University of Hawaii at Hilo 200 West Kawili Street Hilo, HI 96720 Office of Planning - Hawaii CZM Program Hawaii State Department of Business, Economic Development and Tourism P.O. Box 2359 Honolulu, Hawaii 96804 County Agencies Hawaii County Planning Department 25 Aupuni Street Hilo, Hawaii 96720 Hawaii County Council 25 Aupuni Street Hilo Hawaii 96720 Environmental Assessment 4-1 Comments and Coordination Kawailani Intersection Improvements Hawaii County Civil Defense 920 Ululani Street Hilo, Hawaii 96720 Hawaii County Police Department 349 Kapiolani Street Hilo, Hawaii 96720 Hawaii County Fire Department 25 Aupuni Street Hilo, Hawaii 96720 Copies of correspondence from agencies or organizations with substantive comments during the preparation of the EA are included in Appendix 4. 4.2 Public Involvement The following organizations received a letter inviting their participation in the preparation of the Environmental Assessment: o Sierra Club o Hawaii Island Chamber of Commerce The County of Hawaii invited public participation throughout project development. County officials attended "neighborhood meetings" sponsored by the Hawaii County Council representative for the district. In addition, County officials have spoken in person or by telephone with various community members and community association leaders. The process has generated evidence of the perceived effects of the project on neighborhood issues, such as identity, cohesion, and safety. A public meeting will be held during the comment period for the EA. 4.3 Coordination Correspondence Two letters were received as a result of coordination letters with federal agencies (or state agencies mandated with administering federal laws or programs) with jurisdiction over aspects of the project and/or expertise in areas of concern: U.S. Fish and Wildlife Service Hawaii State Historic Preservation Division These letters are contained at the beginning of Appendix 4 and are referenced in appropriate sections of this document. Environmental Assessment 4-2 Comments and Coordination Kawailani Intersection Improvements 5 LIST OF DOCUMENT PREPARERS This Environmental Impact Statement was prepared for the Federal Highway Administration and the County of Hawaii by Okahara and Associates jointly with Ron Terry, Ph. D. The following companies and individuals were involved: Co -Consultant Okahara and Associates 200 Kohola Street Hilo, Hawaii 96720 Masa Nishida Civil Engineer Co -Project Manager Co -Consultant GeoMetrician Associates HC 2 Box 9575 Keaau, Hawaii 96749 Ron Terry Environmental Specialist Principal Investigator Sub -Consultants Y. Ebisu Acoustic Engineer Barry Neal Air Quality Specialist Randall Okaneku Traffic Engineer B.S. California Polytechnic, Civil Engineering, 1971 P.E. Civil Engineering, State of Hawaii Ph.D. Louisiana State University, Geography, 1988 M.S. University of Hawaii, Elect. Eng., 1969 P.E. Electrical Engineering, State of Hawaii M.S. University of Hawaii, Meteorology, 1976 M.S. University of Hawaii, Civil Eng., 1978 P.E. Civil Engineering -Transportation, State of Hawaii Environmental Assessment 5-1 Document Preparers Kawailani Intersection Improvements 6 STATE OF HAWAII ENVIRONMENTAL ASSESSMENT FINDINGS Section 11-200-12 of the State Administrative Rules sets forth the criteria by which the significance of environmental impacts shall be evaluated. The following discussion paraphrases these criteria individually and evaluates the project's relation to each. 1. The project will not involve an irrevocable commitment or loss or destruction of any natural or cultural resources. The area is entirely developed for urban uses of residences and small commercial. No natural or cultural resources are present or would be affected. The State Historic Preservation Division has determined that no cultural resources are present. 2. The project will not curtail the range of beneficial uses of the environment. No future beneficial use of the environment will be affected in any way by the proposed project. 3. The project will not conflict with the State's long-term environmental policies. The State's long term environmental policies are set forth in Chapter 344, HRS. The broad goals of this policy are to conserve natural resources and enhance the quality of life. A number of specific guidelines support these goals. No aspect of the proposed project conflicts with these guidelines. The project supports a number of guidelines, including those encouraging transportation systems in harmony with the lifestyle of the people and the environment. 4. The project will not substantially affect the economic or social welfare of the community or State. The improvements will benefit the social and economic welfare of the Waiakea area of South Hilo by providing safer road intersections for residents and visitors. 5. The project does not substantially affect public health in any detrimental way. No effects to public health are anticipated. 6. The project will not involve substantial secondary impacts, such as population changes or effects on public facilities. No adverse secondary effects are expected. The project will not enable development. 7. The project will not involve a substantial degradation of environmental quality. Permits mandating best management practices for soil erosion and sediment control will ensure that the project will not degrade environmental quality in any substantial way. Environmental Assessment 6-1 State of Hawaii Findings Kawailani Intersection Improvements 8. The project will not substantially affect any rare, threatened or endangered species of flora or fauna or habitat. No endangered species of flora or fauna are known to exist on the project site or would be affected in any way by the project. 9. The project is not one which is individually limited but cumulatively may have considerable effect upon the environment or involves a commitment for larger actions. Most adverse impacts related to the project are negligible and can be mitigated through proper enforcement of permit conditions. Therefore, such impacts will not accumulate in relation to other projects. 10. The project will not detrimentally affect air or water quality or ambient noise levels. The project will have negligible effects in terms of water quality. There will be an overall benefit in regard to air quality. Noise impacts will occur but can be largely mitigated through noise reduction barriers. 11. The project will not affect nor would it likely to be damaged as a result of being located in an environmentally sensitive area, such as flood plains, tsunami zones, erosion -prone areas, geologically hazardous lands, estuaries, fresh waters or coastal waters. The project does not impact any floodways. Although the project is located in a zone exposed to some earthquake and volcanic hazard, there are no reasonable alternatives. 12. The project will not substantially affect scenic vistas and viewplanes identified in county or state plans or studies. No viewplanes mentioned in the Hawaii County General Plan or any other County or State plan is present or would be affected. 13. The project will not require substantial energy consumption. Negligible amounts of energy input will be required for vegetation removal and site preparation. For the reasons above, the proposed project is not expected to have any significant effect in the context of Chapter 343, Hawaii Revised Statues and section 11-200-12 of the State Administrative Rules. The Hawaii County Department of Public Works anticipates the issuance of a Finding of No Significant Impact (FONSI). Environmental Assessment 6-2 State of Hawaii Findings Kawailani Intersection Improvements REFERENCES Belt, Collins and Associates. 1975. Hilo Community Development Plan. Hilo: Hawaii County Planning Dept. Hawaii State Department of Transportation (DOT). 1994. Bike Plan Hawaii: A State of Hawaii Master Plan. Honolulu: DOT. Hawaii State Department of Transportation (DOT). 1998. Hawaii Long Range Land Transportation Plan. Rept. prep. in coop. with Hawaii County Depts. of Public Works and Planning and U.S. Dept. of Transportation. Heliker, C. 1990. Volcanic and Seismic Hazards on the Island of Hawaii. Washington: U.S. GPO. Macdonald, G.A., A.T. Abbott, and F.L. Peterson. 1986. Volcanoes in the Sea: The Geology of Hawaii. 2nd ed. Honolulu: University of Hawaii Press. R. M. Tow iII Corp. 1994. Engineering Report for Urban Intersection Study, Island of Hawaii, Project No. FIS 94-07 (02-H-01). Prep. for Hawaii County Dept. Public Works. Transportation Research Board. 1985. Highway Capacity Manual. Special Report 209. Washington: U.S. GPO. U.S. Bureau of the Census. 1991. 1990 Census of Population. General Population Characteristics. 1990 CP -1-13. Washington: U.S. GPO. U.S. Soil Conservation Service. 1973. Soil Survey of Island of Hawaii, State of Hawaii. Washington: U.S. GPO. U.S. Soil Conservation Service. 1981. Erosion and Sediment Control Guide for Hawaii. Honolulu: USSCS. University of Hawaii at Manoa, Dept. of Geography. 1983. Atlas of Hawaii. 2nd ed. Honolulu: University of Hawaii Press. Wolfe, E.W., and J. Morris. 1996. Geologic Map of the Island of Hawaii. USGS Misc. Investig. Ser. Map 1-2524-A. Environmental Assessment tt- 1 References APPENDIX 1 TRAFFIC ASSESSMENT DRAFT TRAFFIC IMPACT ANALYSIS REPORT FOR THE PROPOSED KAWAILANI STREET IMPROVEMENTS AINAOLA DRIVE/POHAKULANI STREET TO IWALANI STREET PREPARED FOR OKAHARA & ASSOCIATES, INC. PREPARED BY THE TRAFFIC MANAGEMENT CONSULTANT DRAFT TRAFFIC IMPACT ANALYSIS REPORT FOR THE PROPOSED KAWAILANI STREET IMPROVEMENTS AINAOLA DRIVE/POHAKULANI STREET TO IWALANI STREET PREPARED FOR OKAHARA & ASSOCIATES, INC. NOVEMBER 6, 1998 PREPARED BY TMC THE TRAFFIC MANAGEMENT CONSULTANT --�) ?�' RANDALL S. OKANEKU, P. E., PRINCIPAL • 1188 BISHOP STREET, SUITE 1907 • HONOLULU, HAWAII 96913 Table of Contents Page Chapter 1. Introduction 1 I. Purpose and Scope of the Study 1 A. Purpose 1 B. Scope 1 II. Project Description 2 III. Background 2 A. General 2 B. Traffic Safety 2 C. Traffic Signal Warrant Analysis 3 Chapter 2. Existing Conditions 4 I. General 4 II. Roadways 4 A. Kawailani Street 4 B. Ainaola Drive 6 C. Iwalani Street 6 D. Pohakulani Street 6 E. Kuhilani Street and Ehenene Place 7 III. Traffic Operations 7 A. General 7 1. Traffic Count Data Collection 7 2. Capacity Analysis Methodology 7 Table of Contents (cont'd) Page B. Existing AM Peak Hour Traffic Analysis 8 1. Iwalani Street and Kawailani Street Intersection 8 2. Ainaola Drive/Pohakulani Street and 18 Kawailani Street Intersection 10 C. Existing PM Peak Hour Traffic Analysis 10 1. Iwalani Street and Kawailani Street Intersection 10 2. Ainaola Drive/Pohakulani Street and Kawailani Street Intersection 12 Chapter 3. Projected Traffic 13 I. Long Range Travel Forecast 13 II. No -Build Scenario 14 A. General 14 B. AM Peak Hour Traffic Analysis Without Project 14 C. PM Peak Hour Traffic Analysis Without Project 16 Chapter 4. Evaluation of Alternatives 18 I. General 18 II. Alternative 1 18 A. Description 18 B. Advantages 19 C. Disadvantages 19 Table of Contents (cont'd) Page III. Alternative 2 19 A. Description 19 B. Advantages 19 C. Disadvantages 22 IV. Alternative 3 22 A. Description 22 B. Advantages 22 C. Disadvantages 22 V. Alternative 4 22 A. Description 22 B. Advantages 25 C. Disadvantages 25 VI. Alternative 5 25 A. Description 25 B. Advantages 25 C. Disadvantages 27 VII. Alternative 6 27 A. Description 27 B. Advantages 30 C. Disadvantages 30 VIII. Alternative 7 30 A. Description 30 B. Advantages 32 C. Disadvantages 32 Table of Contents (cont' Page IX. Summary 32 X. Preferred Alternatives 33 A. General 33 B. Scheme A 33 C. Scheme B 33 Chapter 5. Traffic Impact Analysis 37 I. General 37 II. Scheme A 38 A. Year 2018 AM Peak Hour Traffic With Scheme A 38 B. Year 2018 PM Peak Hour Traffic With Scheme A 38 III. Scheme B 41 A. Year 2018 AM Peak Hour Traffic With Scheme B 41 B. Year 2018 PM Peak Hour Traffic With Scheme B 43 IV. Capacity Analysis Summary 45 V. Pohakulani Street Traffic Assessment 46 A. General 46 B. Scheme A 46 C. Scheme B 46 Chapter 6. Recommendations and Conclusions 49 I. Recommendations 49 A. General 49 B. Intersection of Ainaola Drive/Pohakulani Street and Kawailani Street 49 Table of Contents (cont'd) Page C. Intersection of Iwalani Street and Kawailani Street 50 D. Intersection of Pohakulani Street and Ainaola Drive 50 If. Conclusions 50 List of Figures Page Figure 1. Vicinity Map 5 Figure 2. Existing AM Peak Hour Traffic 9 Figure 3. Existing PM Peak Hour Traffic 11 Figure 4. Year 2018 AM Peak Hour Without Improvements 15 Figure 5. 2018 PM Peak Hour Traffic Without Project 17 Figure 6. Alternative 1 20 Figure 7. Alternative 2 21 Figure 8. Alternative 3 23 Figure 9. Alternative 4 24 Figure 10. Alternative 5 26 Figure 11. Alternative 6 28 Figure 12. Examples of Modem Roundabouts 29 Figure 13. Alternative 7 31 Figure 14. Alternative 1A 34 Figure 15. Alternative 1B 36 Figure 16. Year 2018 AM Peak Hour Traffic with Scheme A 39 Figure 17. Year 2018 PM Peak Hour Traffic With Scheme A 40 Figure 18. Year 2018 AM Peak Hour Traffic With Scheme B 42 Figure 19. Year 2018 PM Peak Hour Traffic With Scheme B 44 Figure 20. Pohakulani Street Alignment 47 Uhapter 1. Introduction I. Purpose and Scope of the Study A. Purpose The purpose of this study is to analyze the traffic impacts resulting from the proposed improvements of Kawailani Street at its intersections at Ainaola Drive/Pohakulani Street and at Iwalani Street. This report presents the findings and recommendations of the traffic study. B. Scope The scope of this study includes: 1. Description of the proposed project. 2. Description of the study area. 3. Evaluation of existing roads. 4. Analysis of existing peak hour traffic conditions. 5. Development of peak hour traffic forecasts for the Year 2018. 6. Analysis of the Year 2018 peak hour traffic under the "No -Build" Scenario. 7. The evaluation of alternative improvements at the study intersections. 8. Analysis of the Year 2018 peak hour traffic under two preferred alternative improvement plans. 9. Recommendation of improvements based upon the findings of this study. Kawailani Street Improvements Introduction Ainaola Drive/Pohakulani Street to Iwalani Street Project Description II. Project Description The proposed project, located in South Hilo, Hawaii, would consist of traffic improvements at the Kawailani Street intersections at Iwalani Street and at Ainaola Drive/Pohakulani Street. Kawailani Street, Ainaola Drive, and Iwalani Street are part of a network of streets in the vicinity. While the traffic forecast does account for other long range traffic improvements, the traffic analysis, contained herein, focuses on the study intersections and does not analyze the impacts of alternative system -wide improvements, i.e., improving alternative routes that may divert traffic from the study intersections. This study evaluates seven (7) alternative concepts for traffic improvements at these intersections and selects two alternatives for further analysis. The alternative improvement plans consider: traffic signalization; the widening/upgrading of existing roadways; the realignment of roadways; and non -traffic signal control applications. In addition, the traffic impact analysis includes the assessment of future traffic conditions without any improvements. III. Background A. General The "Urban Intersection Study" (UIS), dated October 1994, was prepared for the County of Hawaii Department of Public Works. The intersection of Kawailani Street and Iwalani Street along with thirteen (13) other intersections was evaluated in terms of traffic volumes, congestion, delays, and traffic safety. B. Traffic Safety The UIS indicated that a total of fourteen (14) accidents were reported at the intersection of Kawailani Street and Iwalani Street between the Years 1991 and 1993. Five (5) of those accidents involved an injury. The Kawailani Street/Iwalani Street intersection ranked first in the number of injury accidents relative to the peak hour volume; third in the number of injury accidents relative to the 24-hour volume, second in the number of total accidents relative to the peak hour volume, and third in the number of total accidents relative to the 24-hour volume. According to the schematic accident diagram depicted in the UIS, six (6) of the accidents were of the type that may be mitigated by traffic signal control, i.e., involving right angle or left turn collisions. 2- Kawailani Street Improvements Introduction Ainaola Drive/Pohakulani Street to Iwalani Street Background C. Traffic Signal Warrant Analysis The UIS also indicated that the intersection of Kawailani Street and Iwalani Street met four warrants for traffic signals according to the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD). These warrants include Warrant 1 "Minimum Vehicular Volume", Warrant 2 "Interruption of Continuous Traffic", Warrant 9 "Four Hour Volumes", and Warrant I 1 "Peak Hour Volume". Because of the proximity of the intersection of Kawailani Street and Ainaola Drive/Pohakulani Street to the Kawailani Street/Iwalani Street intersection, both intersections are analyzed in this study. -3- Chapter 2. Existing Conditions I. General The existing land use in the vicinity of the study intersections is primarily residential. The only exception is the Wiki Wiki Mart on the southwest comer of the intersection of Kawailani Street and Ainaola Drive/Pohakulani Street. The street system in South Hilo is a grid network, comprised of well -spaced east - west collectors streets and closely -spaced north -south streets. The exception to the north -south and east -west orientation of the road network is Ainaola Drive, which cuts diagonally across the street grid. The northeast -southwest alignment of Ainaola Drive provides a direct route for area residents traveling to and from the Waiakea School complexes, the University of Hawaii, and Hilo Town. Figure 1 depicts the vicinity of the study area. II. Roadways A. Kawailani Street Kawailani Street is a two lane, two way, east -west major collector street between Kanoelehua Avenue and Kupulau Road. Kawailani Street intersects Ainaola Drive/Pohakulani Street and Iwalani Street at unsignalized intersections. No provisions for exclusive turning lanes exist on Kawailani Street at Ainaola Drive/Pohakulani Street or at Iwalani Street. -4- Kawailani Street Improvements Existing Conditions Ainaola Drive/Pohakulani Street to Iwalani Street Roadways Figure 1. Vicinity Map .5. Kawailani Street Improvements Existing Conditions Ainaola DriveRohakulani Street to Iwalani Street Roadways The existing right-of-way width on Kawailani Street varies between 50 feet and 60 feet between Ehenene Place/Kuhilani Street and Ainaola Drive/Pohakulani Street. The Kawailani Street right-of-way width reduces to 40 feet, east of Ainaola Drive/Pohakulani Street. B. Ainaola Drive Ainaola Drive is a two lane, two way major collector street, which generally runs southwest -northeast, between the Waiakea Homesteads area and Kawailani Street. The existing right-of-way width on Ainaola Drive is 60 feet. Ainaola Drive is yield -controlled at its skewed intersection with Kawailani Street. Ainaola Drive, together with Iwalani Street, forms a major north -south thoroughfare in area, via a short connection on Kawailani Street. C. Iwalani Street Iwalani Street is two lane, two way, north -south major collector street between Haihai Street to the south and Puainako Street to the north. Iwalani Street continues as Kawili Street to the University of Hawaii at Hilo, and into Hilo Town. Iwalani Street is stop -controlled at its four -legged intersection with Kawailani Street. The existing right-of-way on Iwalani Street is 80 feet wide north of Kawailani Street, and 40 feet wide south of Kawailani Street. D. Pohakulani Street Pohakulani Street is a two lane, two way local street, oriented in the north -south directions. The north and south legs of the intersection of Pohakulani Street at Kawailani Street are cul-de-sac roadways. Pohakulani Street continues northward to Puainako Street; however, a section of the street, midway between Puainako Street and Kawailani Street, is unimproved and does not permit through traffic. Pohakulani Street, Kawailani Street, and Ainaola Drive form a five -legged unsignalized intersection, which is comprised of three separate junctions between each pair of intersecting roadways. The northbound Pohakulani Street is stop -controlled at Ainaola Drive and also at Kawailani Street. Northbound Pohakulani Street at Ainaola Drive provides a two lane approach, an exclusive right turn lane toward Kawailani Street, and a shared through/left turn lane. Southbound Pohakulani Street, between Kawailani Street and Ainaola Drive, also provides a two lane approach. One lane is dedicated to traffic turning right to southwest bound M Kawailani Street Improvements Existing Conditions Ainaola Drive/Pohakulani Street to Iwalani Street Traffic Operations Ainaola Drive. The other lane continues in the southbound direction to Pohakulani Street, yielding the right-of-way to northeast bound Ainaola Drive. The existing right-of-way on Pohakulani Street is 40 feet wide. E. Kuhilani Street and Ehenene Place Kuhilani Street is a two lane, two way, minor north -south collector road, located west of Pohakulani Street, and between Kawailani Street and Puainako Street. Kuhilani Street is the north leg of its four -legged unsignalized intersection with Kawailani Street, opposite Ehenene Place, a cul-de-sac road. The right-of-way on Kuhilani Street is 50 feet wide. The right-of-way width on Ehenene Place varies between 50 feet and 60 feet. III. Traffic Operations A. General 1. Traffic Count Data Collection The field investigation, conducted in October 1997, consisted of a visual inspection of the roadways and peak period traffic conditions and manual traffic count surveys. The surveys were conducted from 6:00 AM to 8:45 AM and from 3:00 PM and 6:00 PM at the following intersections: a. Kawailani Street and Kuhilani Street/Ehenene Place b. Kawailani Street and Ainaola Drive/Pohakulani Street c. Kawailani Street and Iwalani Street 2. Capacity Analysis Methodology The highway capacity analysis performed for this study is based upon procedures presented in the "Highway Capacity Manual" (HCM), Special Report 209, Transportation Research Board, and the "Highway Capacity Software", Federal Highways Administration. Level of Service (LOS) is "defined as a qualitative measure describing operational conditions within a traffic stream". Several factors are included in determining LOS such as: speed, delay, vehicle density, freedom to maneuver, traffic interruptions, driver comfort, and safety. LOS "A", "B", and "C" are -7- Kawailani Street Improvements Existing Conditions Ainaola Drive/Pohakulani Street to Iwalani Street Traffic Operations considered satisfactory levels of service. LOS "D" is generally considered a "desirable minimum" operating level of service. LOS "E" is an undesirable condition and LOS "F" is an unacceptable condition. From an operational perspective, LOS "F" results in traffic queues backing up from downstream intersections, affecting the traffic flow at the study intersection. LOS "F" also can occur when the traffic demand meets or exceeds the intersection's capacity, which results in queuing from the study intersection. From a planning perspective, LOS "F" indicates that the traffic demand exceeds the roadway's carrying capacity. B. Existing AM Peak Hour Traffic Analysis The existing AM peak hour of traffic occurred between 7:00 AM and 8:00 AM during the field investigation. The dominant directions of traffic during the AM peak hour were eastbound on Kawailani Street, and northeast bound on Ainaola Drive, turning right onto eastbound Kawailani Street. The heavy left tum demand on eastbound Kawailani Street at Iwalani Street resulted in occasional queuing on eastbound Kawailani Street beyond and onto Ainaola Drive. Figure 2 depicts the existing AM peak hour of traffic and the results of the capacity analysis. 1. Iwalani Street and Kawailani Street Intersection Both approaches of Iwalani Street at its intersection with Kawailani Street operated at LOS "F" during the existing AM peak hour of traffic. The LOS "F" conditions resulted in extreme delays experienced by motorists turning onto or proceeding through the intersection. The single lane approaches also resulted in delays of the right tum movements. The [walani Street delays were mitigated when motorists on Kawailani Street permitted motorists on Iwalani Street to tum onto or cross Kawailani Street. The left tum movement on eastbound Kawailani Street operated at LOS "B". However, the left turn movement from the one lane approach caused delays to through traffic, which was evident by the queuing on eastbound Kawailani Street that was observed during the AM peak hour of traffic. Existing AM peak hour volumes on Kawailani Street meet the volume warrant for an exclusive left turn lane on eastbound Kawailani Street at Iwalani Street. ME Kawailani Street Improvements Existing Conditions Ainaola DriveiPohakulani Street to Iwalani Street Traffic Operations POHAKULANI STREET 10 N I 7J�i1 KAWAILANI STREET m —7� 472 8 1e04 J� Ij 1 IWALANI STREET 5 89 381 434 <-- 1 260 5 y5 175 5 14 KAWAILANI pp KAWAILANI STREET 1n STREET �� 20 9 IWALANI STREET 2X 1a B �b AINAOLA DRIVE i>:4 POHAKULANI STREET NOT TO SCALE LEGEND 90 �T TRAFFIC MOVEMENT VOLUME (VPH) LANE CONTROL © LEVEL OF SERVICE (UNSIGNALIZED CONDITION) © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 2. Existing AM Peak Hour Traffic ze Kawailani Street Improvements Existing Conditions Ainaola Drive/Pohakulani Street to Iwalani Street Traffic Operations 2. Ainaola Drive/Pohakulani Street and Kawailani Street Intersection The northbound approach of Pohakulani Street at Kawailani Street operated at LOS "E" during the existing AM peak hour of traffic. The southbound approach of Pohakulani Street operated at LOS "F". The right turn movement from Ainaola Drive onto Kawailani Street operated at LOS "C". The side street delays were a result of eastbound queues on Kawailani Street that backed up from Iwalani Street. These delays again were mitigated when motorists on Kawailani Street permitted motorists on Ainaola Drive/Pohakulani Street to tum onto or proceed through the intersection. Existing AM peak hour volumes on Kawailani Street meet the volume warrant for an exclusive left tum lane on westbound Kawailani Street at Ainaola Drive/Pohakulani Street. The intersection of Ainaola Drive and Pohakulani Street operated at satisfactory LOS during the existing AM peak hour of traffic. C. Existing PM Peak Hour Traffic Analysis The existing PM peak hour of traffic occurred between 4:30 PM and 5:30 PM during the field investigation. The PM peak hour directions of traffic were reversed from the AM peak hour, i.e., heavy traffic volumes occurred on southbound Iwalani Street, westbound Kawailani Street, and southwest bound Ainaola Drive. The heavy left tum movement on westbound Kawailani Street at Ainaola Drive/ Pohakulani Street resulted in occasional queuing on Kawailani Street, which extended beyond Iwalani Street. The existing PM peak hour traffic and the results of the capacity analysis are depicted on Figure 3. 1. Iwalani Street and Kawailani Street Intersection The southbound approach of Iwalani Street at Kawailani Street operated at LOS "F" during the existing PM peak hour of traffic. The northbound approach of Iwalani Street operated at LOS "E". Longer delays were observed on both approaches when the westbound queue on Kawailani Street extended beyond Iwalani Street. Motorists on Kawailani Street permitted motorists on Iwalani Street to tum onto or cross Kawailani Street. Existing PM peak hour volumes on Kawailani Street again meet the volume warrant for an exclusive left turn lane on eastbound Kawailani Street at Iwalani Street. -io- Kawailani Street Improvements Existing Conditions Ainaole Orive/Pohakulani Street to Iwalani Street Traffic Operations POHAKULANI STREET 8 V8 3 0 KAWAILANI ai STREET m3 292 32 8 B 512 28 IWALANI STREET 20 19 365 � 7 554 r C 334 �L��LL 6 505 22 26 KAWAILANI KAWAILANI AINAOLA DRIVE 4 2251 POHAKULANI STREET STRE ET �.pj� STREET 143 �10 2(1 'j` X13 �)� � 362 28 IWALANISTREET NOT TO SCALE LEGEND TRAFFIC MOVEMENT VOLUME (VPH) LANE CONTROL LEVEL OF SERVICE (UNSIGNALIZED CONDITION) © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 3. Existing PM Peak Hour Traffic 11- Kawailani Street Improvements Existing Conditions Ainaola Drive/Pohakulani Street to Iwalani Street Traffic Operations 2. Ainaola Drive/Pohakulani Street and Kawailani Street Intersection Both approaches of Pohakulani Street at Kawailani Street operated at LOS "F" during the existing PM peak hour of traffic. Although the traffic volumes were low on Pohakulani Street, the delays were long, except when motorists on Kawailani Street yielded to traffic turning onto or crossing the intersection. The right tum movement from Ainaola Drive onto Kawailani Street operated at LOS "C". The left turn movement on westbound Kawailani Street operated at LOS "C". However, the left turn movement from the single lane approach caused delays for through traffic, which was evident by the westbound queuing that was observed during the PM peak hour of traffic. Existing PM peak hour volumes on Kawailani Street also meet the volume warrant for an exclusive left turn lane on westbound Kawailani Street at Ainaola Drive/Pohakulani Street. The intersection of Ainaola Drive and Pohakulani Street operated at satisfactory LOS during the existing PM peak hour of traffic. -12- Chapter 3. Projected Traffic I. Long Range Travel Forecast The travel forecast, presented in this study, was developed from the Hawaii Long Range Land Transportation Plan Draft Final Report, January 1998 (HLRLTP), prepared for the State of Hawaii Department of Transportation, in cooperation with the County of Hawaii Department of Public Works and Planning Department. The HLRLTP used the Year 1992 as its base year, and the Year 2020 as its planning horizon for the land use inventory and travel forecasts. A travel forecast model was developed by dividing the island into "traffic analysis zones" (TAZ), i.e., a definable area in which all trips originating within the TAZ have destinations in other TAZs. These trips are assigned to a network model, which represents the roadway system. Future traffic assignments were not presented in the HLRLTP; therefore, the rate of growth of traffic in the vicinity of the project was developed, based upon the increase in the total trips generated by TAZs within the immediate vicinity of the proposed project. These TAZs included the areas identified in the HLRLTP as: TAZ 55 - Lower Puainako ° TAZ 56 - Kinoole-Puainako ° TAZ 64 - Komohana TAZ 65 - Ainaola ° TAZ 66 - Upper Puainako TAZ 67 - Waiakea Uka 13- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street Projected Traffic No -Build Scenario The average annual growth in trip generation for these TAZs was 1.1 percent per year. This growth rate is applied uniformly over the existing (1998) peak hour traffic volumes and projected over a twenty-year time frame to estimate the Year 2018 peak hour traffic demands. II. No -Build Scenario A. General The Year 2018 traffic operations are analyzed without the proposed improvements or the "No -Build" scenario, i.e., under existing roadway conditions. While it is highly unlikely that highway improvements would not be implemented by the Year 2018, it is even more unlikely that the peak hour traffic demands, presented in this section, would actually occur under the extremely congested conditions. In areas where the projected demands exceed the intersection capacity, traffic would most likely divert to alternative routes, where traffic improvements has been implemented. Otherwise, motorists could adjust their travel patterns to avoid the peak hours of traffic, resulting in longer peak periods instead of higher peak hour traffic demands. The purpose of analyzing the "No -Build" scenario is to assess the benefits derived by the proposed improvements by comparing the Year 2018 traffic operations under existing roadway conditions and under the improved roadway conditions. B. AM Peak Hour Traffic Analysis Without Project Both Iwalani Street approaches at Kawailani Street are expected to continue to operate at LOS "F". The left turn movement on eastbound Kawailani Street is expected to still operate at LOS "C"; however, queue lengths can be expected to extend beyond Ainaola Drive more frequently. The right turn movement from Ainaola Drive to eastbound Kawailani Street is expected to operate at LOS "F". Both approaches of Pohakulani Street at Kawailani Street are expected to operate at LOS "F". Queuing on Ainaola Drive from Kawailani Street can be expected to increase the delays experienced on northbound Pohakulani Street at Ainaola Drive. Figure 4 depicts the Year 2018 AM peak hour traffic and the results of the capacity analysis without any traffic improvements. _14- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street Projected Traffic No -Build Scenario POHAKULANI STREET IWALANISTREET 10 110 ' L�—___�� ' 2M 534 r- 12 � �L `Y 17 y7_4 154 (J .J� y 6 �L 1 215 6 Q 17 KAWAILANI QQ KAWAILANI q `>T KAWAILANI STREET 666 STREET b b STREET 1 1 595 420 25 9 2 h 'j` 130 581 lJ �762 10 11 IWALANI STREET B I 222 5 CS 7 22 N Q �] 2 NOT TO SCALE LEGEND AINAOLA DRIVE 90 22_�P TRAFFIC MOVEMENT VOLUME (VPH) 573 LANE CONTROL (� �y LEVEL OF SERVICE (UNSIGNALIZED CONDITION) 5 POSTR ETT NI © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 4. Year 2018 AM Peak Hour Without Improvements 15- Kawailani Street Improvements Projected Traffic Ainaola Drive/Pohakulani Street to Iwalani Street No -Build Scenario C. PM Peak Hour Traffic Analysis Without Project The northbound approach of Iwalani Street at Kawailani Street is expected to deteriorate to LOS "F" during the Year 2018 PM peak hour of traffic. Traffic operations on all legs of the intersection would be affected by the queuing on westbound Kawailani Street at Ainaola Drive/Pohakulani Street. The left turn movement on westbound Kawailani Street is expected to operate at LOS "F" during the Year 2018 PM peak hour of traffic without the proposed improvements. The northbound and southbound approaches of Pohakulani Street and Kawailani Street are expected to continue to operate at LOS "F". The left turn/through movement on the northbound approach of Pohakulani Street at Ainaola Drive is expected to operate at LOS "E" during the Year 2018 PM peak hour of traffic without the proposed improvements. The Year 2018 PM peak hour traffic without improvements and the results of the capacity analysis are depicted on Figure S. -16- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street POHAKULANI STREET 10 djl-)7 4 KAWAILANI pp STREET 1n 4 359 39 BB 631 34 Projected Traffic No -Build Scenario IWALANI STREET 25 23 449 1 663 411 7, `j 7 622 27 32 KAWAILANI /17KAWAILANI / I I AINAOLA DRIVE 278S 1 POHAKULANI STREET FAS 90 STRE ET STREET 176 12 B 216 446 34 IWALANI STREET NOT TO SCALE LEGEND TRAFFIC MOVEMENT VOLUME (VPH) LANE CONTROL LEVEL OF SERVICE (UNSIGNALIZED CONDITION) LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 5. 2018 PM Peak Hour Traffic Without Project -17- Chapter 4. Evaluation of Alternatives I. General A total of seven (7) alternative alignments were developed for the Kawailani Street improvements. The various alternatives included realigning and/or widening existing streets that would require land acquisition and, in some cases, the demolition of homes. The alternatives were evaluated in terms of the following criteria: feasibility, impacts to residents, right-of-way acquisition, overall costs, traffic operations, and environmental impacts. The alternative alignments have the following common features: ° Widening Kawailani Street between Kuhilani Street/Ehehene Place and Iwalani Street to provide for exclusive left turn lanes(s) and additional through lane(s). ° Widening the southbound approach of lwalani Street at Kawailani Street to provide for an exclusive right tum lane. ° Realigning Ainaola Drive at Kawailani Street to eliminate/reduce the skewed intersection. It. Alternative 1 A. Description Under Alternative 1, Ainaola Drive is proposed to be realigned to intersect Kawailani Street opposite the north leg of Pohakulani Street. Realigning Ainaola Drive to form a more conventional four -legged intersection increases the intersection spacing on Kawailani Street between Ainaola Drive/Pohakulani Street 18- Kawadani Street Improvements Evaluation ofAltematives Ainaola Orive/Pohakuiani Street to Iwalani Street Alternative 2 and Iwalani Street. The south leg of Pohakulani Street would be realigned to intersect Ainaola Drive at a stop -controlled four -legged intersection opposite the Wiki Wiki Mart driveway. The Kawailani Street intersection at Ainaola Drive and at Iwalani Street would be traffic signalized. Alternative 1 is depicted on Figure 6. B. Advantages 1. Alternative 1 would be the least disruptive to the environs in that it involves minimum modification of existing street alignments. 2. Right-of-way acquisition is not expected to involve the demolition of homes. 3. Traffic flows would remain along existing corridors and, therefore, do not significantly impact previously unaffected residents. C. Disadvantages The spacing between the Kawailani Street intersections at Iwalani Street and at Ainaola Drive/Pohakulani Street would limit the available storage length for proposed left tum lanes on Kawailani Street. 2. The spacing between the intersections may affect the efficiency of the traffic signal coordination along Kawailani Street. 3. The realignment of the south leg of Pohakulani Street to Ainaola Drive would create a new unsignalized intersection adjacent to the proposed traffic signalized intersection of Kawailani Street and Ainaola Drive/Pohakulani Street. III. Alternative 2 A. Description Alternative 2 is similar to Alternative 1 except that access to the south leg of Pohakulani Street would be provided by a new roadway through an undeveloped lot located further south along Ainaola Drive. Figure 7 depicts Alternative 2. B. Advantages In addition to the advantages listed above under Alternative 1, Alternative 1 would further separate the new intersection between Ainaola Drive and Pohakulani Street from the proposed traffic signals at the intersection of Kawailani Street and Ainaola Drive/Pohakulani Street. E (n D M F m 0 0 m Mimi op 41 L 1. Mimi riAI�S INVIIVMV>i A op L riAI�S INVIIVMV>i A L 1. ------ m O m mIL ----i ..... 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Disadvantages As discussed under Alternative 1, the intersection spacing on Kawailani Street would limit the available left tum storage lengths and may affect the efficiency of the traffic signal coordination. 2. One undeveloped lot would need to be acquired for the new road alignment. IV. Alternative 3 A. Description Alternative 3 is another variation of Alternative 1, in which access to the south leg of Pohakulani Street would be relocated to Heahea Street, which is located further south along Ainaola Drive. Figure 8 depicts Alternative 3. B. Advantages In addition to the advantages discussed under Alternative 1, relocating the Pohakulani Street access to the existing Heahea Street would eliminate an access point along Ainaola Drive. C. Disadvantages 1. As discussed under Alternative 1, the intersection spacing on Kawailani Street would limit the available left tum storage lengths, and may affect the efficiency of the traffic signal coordination. 2. More extensive right-of-way acquisition would involve at least one home. 3. The traffic from Pohakulani Street would be diverted to Heahea Street, affecting residents in the immediate vicinity of the new intersection. 4. The increase in traffic from Pohakulani Street may impact the intersection of Heahea Street and Ainaola Drive. V. Alternative 4 A. Description Alternative 4 is yet another variation of Alternative I in the treatment of the south leg of Pohakulani Street. Under Alternative 4, Pohakulani Street would be relocated to Iwalani Street by constructing a new roadway through an improved residential lot. Figure 9 depicts Alternative 4. -22- N O D C.0 m 03 D m 5 Z iD FT1 ^J 11 ac 2 m 0 MXC Tim O N :0= m O m >om 0-0O x0 _= 0 mzM 0c AN Z m0 z rpt -O I I .Z7 i O I C- m C) NIHON W N M -+ D OOrZ ri Z Z= D arm- o e in -I� m Mm D Z �� nlO*i mDm O M> y m mN -DZ m m =3 L> w � � Y � � -+ NZ Om =D m;o " x mZ 0D �0 9 M K> MZ �. �r Z� m0 = Nm ZN 50 N O D C.0 m 03 D m 5 Z iD FT1 ^J 11 ac 2 m 0 MXC Tim O N :0= m O m >om 0-0O x0 _= 0 mzM 0c AN Z m0 z In ------------ El I 1 , No 1 4 b11VMV>l I � i i; i rpt it ii I I i I In ------------ El I 1 , No 1 4 b11VMV>l I � i i; i I it ii I I i I a -- nor - -I J NIHON W N N -+ D OOrZ ri Z Z= D arm- m0 y z -I� m Mm D Z �� nlO*i mDm O M> y mz ND mN -DZ MM me m =3 L> ZN 0 m� O � -+ NZ Om =D m;o " x mZ 0D �0 O M K> MZ �. �r Z� m0 = Nm O� m� �z r0 �0 mm:me Dz D NA � Mm m� v� m in:c Z z m m M Z c� D � m m N C) V) x� 0 m z 2 � �_ O � mo z �z v O M 0 In z w 41 El I I ra 1L ON =or 13�&LS INYIIVMVA U) M I I ra 1L ON =or 13�&LS INYIIVMVA > ooz n < 0 Z E > 0 'm 'a < > m --I M M rvj mm X < z 1 x � .O m M>m M o L,);r, M> v m Z (n�; -oz --10 0 m E�o m K: r m 0* j> 0 >m — (A Z -M 0M co Z M M — Lf) 0 U) OM 0 I r- >m < m Ln m > r ) > x X > , EjE > a— z > 1; M fN M Z �> L� o ;vz > z —M yr z1; mo 1; (/)M 0 M M > m z ;-04 > M >m N a 0 :jM ;ur- C: rO --j AM mr-x > Ln Z— 7m < U) (n 0 > n z --I;o M 0 r -:E 0 > m — M > Mm m (f) — MS. M m z m X m z M Lo m Ln 0 Ln m C) m z m z ;oz 0 0 Kawailani Street Improvements Ainaola OriveRohakulani Street to Iwalani Street B. Advantages Evaluation of Alternatives Alternative 5 1. Alternative 4 would eliminate an access point along Ainaola Drive as in Alternative 3. 2. It would reduce the traffic along the heavily traveled Ainaola Drive and Kawailani Street by diverting. Pohakulani Street traffic to the less utilized Iwalani Street. 3. It improves access to Pohakulani Street via relatively low volume Iwalani Street. C. Disadvantages The disadvantages discussed under Alternative 1 regarding the intersection spacing and traffic signal coordination would remain. 2. Extensive right-of-way acquisition would involve at least one home. 3. The diverted traffic from Pohakulani Street would affect residents along Iwalani Street between Kawailani Street and Haihai Street. VI. Alternative 5 A. Description Under Alternative 5, Ainaola Drive is proposed to be realigned to the existing Ehenene Place alignment, intersecting Kawailani Street opposite Kuhilani Street. The intersection of Kawailani Street and Ehenene Place/Kuhilani Street would be signalized, in addition to the Iwalani Street intersection. The Pohakulani Street intersection also may require traffic signalization. Figure 10 depicts Alternative 5. B. Advantages 1. The intersection spacing on Kawailani Street, between the heavily utilized Ainaola Drive and Iwalani Street, would be increased almost two -fold, providing more left tum storage length between intersections. 2. A portion of the Ainaola Drive traffic demand would be diverted to Kuhilani Street. -25- OEM n 0 z run T mZ= O Dc - - IM cn x -N - ' mD - - - m (� q M m �p �xm z-0 r- 0 --- >00 i ;ovm -- Ox- zDG R D C moZ NJ •�O"z'IzC?m 7 fm E& It a Imply -OL L4 PO .' D (� DK: z-0 r- 0 MCA= 0 M < z c�mzx� K -z- zDG D •�O"z'IzC?m m�vmiONm F5 --q --,---xND M NO m -1 z M07<0 m zgm0 � m c_ 1 m • Z = z -+ N i m i Zc . 0 7 fm E& It a Imply 81S O>iVNIVnd'� n= z !' '1, im �'' D -OL L4 PO .' D (� DK: z-0 r- 0 MCA= 0 M < z c�mzx� K -z- zDG D •�O"z'IzC?m m�vmiONm F5 --q --,---xND M NO m -1 z M07<0 m zgm0 � m c_ SD r- • Z = z -+ N i m i Zc . 0 Z z z D r r 2 W - �� z > m m N M O _ m D Oo M Dm z O i D O � r-; i D z r� O C M cn m z m >=jM O -u D z m NC Z n m= -n D - -- m D - x - � (AM � m M m rx m = r-MmI ' Lc mm m -n z m z N N D .-j f> f 81S O>iVNIVnd'� n= z !' '1, im �'' D -OL L4 PO (� DK: z-0 < Om-<m zDG m�vmiONm F5 m =vr- -1 z M07<0 z � m c_ SD Mg z lmo m M -+ N 0 `{ D -I O D z > m M r- Z =! O \ (n ? D z Z O D i D z E O O C z = D z mm D Z O _0 Z - A x D m M m m � O z N N r -nO � O m M 0 Kawailani Street Improvements Evaluation of Alternatives Ainaola Drive/Pohakulani Street to Iwalani Street Alternative 6 C. Disadvantages 1. The intersection of Pohakulani Street and Kawailani Street also may require traffic signalization. 2. Right-of-way acquisition would involve two homes on Ehenene Place. 3. Residents along Ehenene Place would be impacted by Ainaola Drive traffic. 4. Residents along Kuhilani Street would be impacted by Ainaola Drive traffic, diverted from Iwalani Street. VII. Alternative 6 A. Description Alternative 6 is most unconventional departure from the other alternatives. This alternative would involve an updated version of an "Old World" intersection: the "modern roundabout", also known as a "traffic circle". A roundabout is an at -grade intersection, where two or more roadways intersect at a wide, one-way, circular roadway containing an island in the center of the intersection. The roadway approaches are widened to provide for multi -lane entries to the roundabout. Traffic on all approaches must yield to traffic on the roundabout, tum right to enter the circular roadway, and tum right again to exit at the appropriate leg of the intersection. The modem roundabout has experienced a revival of sorts on the mainland United States. A modern roundabout has yet to be implemented in the State of Hawaii. However, it is seriously being considered as an alternative to traffic signals on Oahu and Molokai by the responsible State and County transportation agencies. Figure 11 depicts Alternative 6. Examples of modem roundabouts, depicted on Figure 12, are taken from "Roundabout Design Guidelines", Ourston & Doctors, 1995. 27- D m m z w o M 0 =m= mAo mr-m O N AA m O m >0m ADO Ox S D m m z 0 0c mm z Z 1 1 i 1332115 INV -I IVMV>i C- -4 ioA P� m D (� _....._.... _. - - --- -- wr O m— Z-----`-- -- --- ---- +--- --- --- ! - -- — — 41 �hlf N rnmin m --- a m 1 i 1332115 INV -I IVMV>i I i C- -4 ioA P� m D (� _....._.... _. - - --- -- � � O m— Z-----`-- -- --- ---- +--- --- --- ! - -- — — �eAL �hlf N rnmin m --- a m 1 0 0 -"- - - - TI 0 m-0 ---- v �i Z �� N _Qm O M>M r A DD D 70K: Z cDi ;0 0 o 0 O Ln OZEJ D C� nf� n �D'I� �m� D ZO Z ONMZ A\ D00 D--- K:a --- --- -�� - -- - m �Z ••N --- Zrc - ---- - , o� I O=�LI) mD mm co Mo �0 �Z -" M - - �m D N -- DO Z� -�--- i ra=t DS �m -C Om m ZD = D 0 Mm M(;:D m (31 F/- 2 O`er A c m Z 0� �y O A m N N O N �� Cn--- OC C ---- -- -- "-- -- - 0 , -Z1 o m� -- — -' mZ OD AZ O I i � � 1 I WN I N D 2M -n<mmO= fuW ? WN N D 2M -n<mmO= 0 1 0 0 TI 0 m-0 =Af v z� Z �� N _Qm O M>M r A DD D 70K: Z cDi ;0 0 cou) 9mD 0 O Ln OZEJ D C� nf� n �D'I� �m� D ZO Z ONMZ A\ D00 K:a z m �Z ••N Z Zrc o� _ O=�LI) mD mm co Mo �0 �Z > D� mm Crrm �m D N V= DO Z� ra=t DS �m -C Om m ZD = D 0 Mm M(;:D m (31 F/- 2 O`er A c m Z 0� �y O A m N N O N �� OC C •--i D fTi� m Z 0 �rC -Z1 o m� mZ _ AZ O O n -� --i M 0 Kawailani Street Improvements Ainaola DdvelPohakulani Street to lwalani Street Normal Roundabout Evaluation of Alternatives Alternative 6 Mini -roundabout: 4 -Leg Intersection With Flared Approaches I 0� a Ref Roundabout Design Guidelines (Durston & Doctors) Mini -roundabout: 4 -Leg Intersection Without Flared Approaches a V a 0) Y b' Y� LEGEND a Curbed splitter island. b Painted splitter island. Figure 12. Examples of Modern Roundabouts INO Kawailani Street Improvements Evaluation of Alternatives Ainaola Drive/Pohakulani Street to Iwalani Street Alternative 7 B. Advantages 1. Studies have shown that the modem roundabout can be superior to a signalized intersection in terms of carrying capacity, particularly where two or more roadways are heavily traveled ("Roundabout Revolution Comes to America", Leif Ourston, 1992). 2. Studies have shown that the modern roundabout can be superior to a signalized intersection in terms of traffic safety, if properly utilized (Durston). 3. The number of lanes required along Kawailani Street may be reduced, which would decrease the acquisition of additional right-of-way. 4. Right-of-way acquisition for auxiliary lanes on Iwalani Street and Ainaola Drive may be reduced. 5. Vehicular emissions may be reduced as compared to traffic signal controls. 6. Overall traffic delays may be reduced as compared to traffic signal controls. 7. The roundabout would be virtually maintenance -free as compared to a traffic signal system. 8. The roundabout may be more energy efficient relative to vehicle fuel. C. Disadvantages 1. Negotiating the roundabout would require higher levels of driver attention and skill. 2. Right-of-way acquisitions would be higher at the corners of the intersections to accommodate the circular roadway. 3. The modem roundabout is untested in the State of Hawaii. VIII. Alternative 7 A. Description Alternative 7 is identical to Alternative 1 except it proposes to upgrade Pohakulani Street between Kawailani Street and Puainako Street to divert traffic from Iwalani Street. Figure 13 depicts Alternative 7. -30- ;o 0 0 _ ..� c -1-11----.---- Z: X I m�f mem r ` Xm m O� r A W O00 >p X r0 ._- �Dc N moz W: dl; NJ FONzm L HLWN - - - -1-11----.---- I I ; r ` A W N J N c FONzm D z F0 i z a>co x A rn m�zcD D P - _Ir (7 m D I O�ZA� Lf) mG')m0 2m m i -! Z -U -1rrI r- D mDO-im xmx*� Om z? mxrr m �C r m=DzZmm O Z caD - - --- e. — _ mmoo I ! �k. x r o m N��O O '-4 D Mm�m _ ._.___SIP' 01 � r-o c �11 m00Z -- 4 � I oOxO mo Z �;omm G) Z m � Z m ZX c m om 0 z Cm r0� z �m a _II �Zx m --,- - ph fi a 38iS OAVNivnd !lowfLimp �o w 0o HLWN - - - -1-11----.---- --- ; A W N N FONzm D z F0 z a>co x A mr m�zcD D m=D�m ON (7 m D O�ZA� Lf) mG')m0 2m m i -! Z -U -1rrI r- D mDO-im xmx*� Om z? mxrr m �C r m=DzZmm O Z mmoo �k. x r o m N��O O '-4 D Mm�m 4z � r-o c �11 m00Z � oOxO mo Z �;omm O Z m � Z m ZX c m om 0 z Cm r0� z �m a �Zx m a Kawailani Street Improvements Evaluation of Alternatives Ainaola Drive/Pohakulani Street to Iwalani Street Summary B. Advantages In addition to the advantages listed above under Alternative 1, Alternative 7 potentially could reduce traffic on Kawailani Street and on Iwalani Street. C. Disadvantages 1. The realignment of the south leg of Pohakulani Street to Ainaola Drive would create anew unsignalized intersection adjacent to the proposed traffic signalized intersection of Kawailani Street and Ainaola Drive/Pohakulani Street. 2. The cumulative acquisition of right-of-way on Pohakulani Street would be significant. 3. It would divert traffic to Puainako Street. 4. The traffic diverted from Iwalani Street would impact the residents along Pohakulani Street. IX. Summary Table 1 summarizes the ratings of seven alternatives from 1 through 10 (1 being the highest relative to the other alternatives). Table 1. Evaluation of Alternatives Criteria Alternatives 1 2 3 4 5 6 7 Property Acquisition Costs 1 2 7 8 10 9 4 Design/Construction Costs 1 2 6 7 10 7 9 Design 6 5 4 3 1 10 2 Traffic Operations 6 5 4 3 1 10 2 Condemnation of Homes 1 2 5 7 10 3 9 Noise/Air Quality Impacts 1 2 4 6 8 3 9 Overall Rankings 1 2 7 8 8 9 9 Note: Ratings developed by Okahaia. & Associates 32- Kawailani Street Improvements Evaluation of Alternatives Ainaola Drive/Pohakulani Street to Iwalani Street Preferred Alternatives X. Preferred Alternatives A. General Alternatives 1 and 2 have been selected for further analysis based upon the previous discussion. Alternatives 1 and 2 have been further expanded to include two schemes (A and B) for each alternative, for a total of four (4) combinations of alternatives and schemes. Schemes A and B differ in the number of lanes, proposed on Kawailani Street between Ainaola Drive/Pohakulani Street and Iwalani Street. In both Schemes A and B, an exclusive left turn lane would be provided on Kawailani Street at the Wiki Wiki Mart driveway. As discussed previously, the difference between Alternatives 1 and 2 is how access to the south leg of Pohakulani Street would be improved. The treatment of Pohakulani Street does not significantly affect the traffic operations of Schemes A or B, since the traffic volumes on Pohakulani Street are relatively low. Therefore, the traffic impact analysis, contained herein, was performed on Schemes A and B. B. Scheme A Scheme A would provide a four (4) lane section on Kawailani Street, between Iwalani Street and Ainaola Drive/Pohakulani Street. The four lane widening would provide one through lane and an exclusive left tum lane in both directions on Kawailani Street at Ainaola Drive/Pohakulani Street. Ainaola Drive would be realigned to intersect Kawailani Street at a conventional right angle intersection. The four lane widening of Kawailani Street at Iwalani Street would provide an exclusive left tum lane and a shared through/right tum lane in the westbound direction, and an exclusive left tum lane, a through only lane, and a shared through/right tum lane in the eastbound direction. The north leg of Iwalani Street would be widened to provide an exclusive right tum lane in the southbound direction. Alternative I is depicted on Figure 14. C. Scheme B Scheme B would include a five (5) lane section on Kawailani Street, between Iwalani Street and Ainaola Drive/Pohakulani Street. The additional lane on Kawailani Street would provide for double left turn lanes on westbound Kawailani Street at Ainaola Drive. Ainaola Drive also would require widening to provide for two southwest bound lanes to accommodate the double left turn movement. The 33- I ... • ...a-.n.'w.. y .. Own N r G CD U i Kawailani Street Improvements Evaluation of Alternatives Ainaola Drive/Pohakulani Street to Iwalani Street Preferred Alternatives two lanes on Ainaola Drive would be extended to allow traffic to merge into one lane. In addition to the double left turn lanes, the eastbound approach of Kawailani Street at Ainaola Drive/Pohakulani Street would include a shared through/right tum lane. The westbound approach of Kawailani Street would include an exclusive left turn lane and a shared through/right tum lane. As in Scheme A, Ainaola Drive would provide an exclusive right turn lane and shared through/left turn lanes on its approaches. The right turn movement from Ainaola Drive would tum into a separate lane, without conflicting with eastbound traffic on Kawailani Street. The five -lane widening of Kawailani Street would provide an exclusive left turn lane, a through only lane, and a shared through/right turn lane in the eastbound direction at Iwalani Street. The two through lanes on Kawailani Street would merge into one lane east of Kanoelani Street. In the westbound direction, Kawailani Street would provide an exclusive left turn lane and a shared through/right tum lane. The north leg of Iwalani Street would be widened to provide an exclusive right tum lane in the southbound direction. Similar to Ainaola Drive, the right tum movement from southbound Iwalani Street would turn into a separate lane, without conflicting with westbound traffic on Kawailani Street. The center lane on Kawailani Street, between Ainaola Drive/Pohakulani Street and Iwalani Street, is proposed as a two-way left turn lane. The two-way left tum lane becomes an exclusive left turn lane on the westbound approach of Ainaola Drive/Pohakulani Street and the eastbound approach at Iwalani Street. The two-way left turn lane would provide the flexibility for left tum storage in both directions during the peak periods of traffic. During the AM peak period of traffic, the heavy left turn traffic demand from eastbound Kawailani Street to northbound Iwalani Street would utilize the storage capacity of the two-way left tum lane. During the PM peak period, the heavy left turn traffic demand from westbound Kawailani Street to southwest bound Ainaola Drive can utilize the storage capacity of the two-way left tum lane. The two-way left turn lane also would facilitate left turn movements to and from driveways along Kawailani Street. Figure 15 depicts Alternative 113. -35- Chapter 5. Traffic Impact Analysis I. General The Highway Capacity Manual methodology, used in the study, analyzes isolated signalized intersections. Because of the proximity of the study intersections, traffic operations at one intersection may affect the other. Queuing between the study intersections may continue to be problematic. The traffic signal coordination between can facilitate the east -west movements on Kawailani Street or the north -south movements between Ainaola Drive and Iwalani Street, as well as reduce the queuing between intersections. The coordination between the Ainaola Drive/Pohakulani Street and the Iwalani Street intersections should initially be set so that the Kawailani Street green phases would be occur simultaneously at both intersections. Field adjustments can then be made by setting offsets between the adjacent traffic signals to facilitate a traffic movement in a particular direction at a given time of day. In any case a uniform traffic signal cycle length must be selected between the two intersections at any given time of day. The traffic signal cycle length affects the queuing and storage requirements of a turning lane. Shorter cycle lengths service turning movements more often, resulting in shorter queue lengths. Longer cycle lengths increase intersection capacity by reducing the "lost' time between phases, i.e., the start-up time it takes for a stopped queue to begin moving through the intersection and time needed for vehicles to clear the intersection between conflicting phases. An "optimum" traffic signal cycle length can be selected, based upon the intersection spacing, to facilitate a two-way directional flow 37- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street Trak Impact Analysis Scheme A of traffic. The minimum traffic signal cycle lengths were selected in this traffic impact analysis to minimize the queuing between intersections, while maintaining acceptable Levels of Service. Queuing analysis defines queue length in stochastic terms. A 95 percentile queue length of 300 feet indicates that traffic queue lengths of up to 300 feet can be expected to occur about 95 percent of the time, i.e., queue lengths are expected to exceed 300 feet about 5 percent of the time. The 95 percentile design queue length is considered desirable, while the 90 percentile queue length is considered the minimum design criteria. Because of the close spacing of the study intersections, the minimum 90 percentile queue was used as the basis of design. II. Scheme A A. Year 2018 AM Peak Hour Traffic With Scheme A Under the proposed Scheme A traffic improvements, the study intersections would operate at satisfactory Levels of Service, i.e., LOS "C" or better during the AM peak hour of traffic. A sixty (60) second traffic signal cycle was used in the AM peak hour analysis of Scheme A. The Year 2018 AM peak hour traffic with Scheme A is depicted on Figure 16. During the AM peak hour of traffic, the projected left turn demand on eastbound Kawailani Street at Iwalani Street would queue up to 275 feet. The 90 percentile left turn queue is expected to be accommodated by the proposed 290± foot storage lane on eastbound Kawailani Street at Iwalani Street. The projected left tum demand on westbound Kawailani Street at Ainaola Drive/Pohakulani Street is expected to queue up to 150 feet. The proposed 400± foot storage lane is expected to be more than adequate to accommodate the 90 percentile left turn queue on westbound Kawailani Street. B. Year 2018 PM Peak Hour Traffic With Scheme A During the PM peak hour of traffic with Scheme A improvements, the study intersections are expected to continue to operate at LOS "C" or better. A traffic signal cycle length of 60 seconds was again used in the analysis to minimize the queuing between intersections. Figure 17 depicts the Year 2018 PM peak hour traffic with Scheme A. -38- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street KAWAILANI STREET 1 C 581 10 POHAKULANI STREET 6 469 B 216 KAWAILANI STREET AINAOLA DRIVE 9jt�j � 594 C B 154 6 6 Trak Impact Analysis Scheme A IWALANI STREET KAWAILANI STREET 420 C 762 11 110 535 F-- S 17 \� a- KAWAILANI STREET 25 2 130 IWALANI STREET NOT TO SCALE LEGEND 90 TRAFFIC MOVEMENT VOLUME (VPH) \" LANE CONTROL ©� LEVEL OF SERVICE (UNSIGNALIZED CONDITION) © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 16. Year 2018 AM Peak Hour Traffic with Scheme A -39- Kawailani Street Improvements Traffic Impact Analysis Ainaola Drive/Pohakulani Street to lwalani Street Scheme A B 10 � 7 4 KAWAILANI STREET 4 C * 360 39 POHAKULANI STREET L25 449 f---'"' �[ 621 KAWAILANI STREET 5 Z 'j` 289 � e III AINAOLA DRIVE IWALANI STREET 23 682 E—�-'��' 411 7 27 32 KAWAILANI Q— KAWAILANI STREET STREET — — _ 176 � � 12 C 216 34 446 B 3a IWALANI STREET NOT TO SCALE LEGEND 90 TRAFFIC MOVEMENT VOLUME (VPH) \ LANE CONTROL LEVEL OF SERVICE (UNSIGNALIZED CONDITION) © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 17. Year 2018 PM Peak Hour Traffic With Scheme A 40- Kawailani Street Improvements Ainaola Orive/Pohakulani Street to Iwalani Street Tralrc Impact Analysis Scheme 8 The PM peak hour left turn demand from westbound Kawailani Street to southwestbound Ainaola Drive is expected to queue up to 400 feet. The 90 percentile left tum queue is expected to be accommodated within the 400± foot distance between the Ainaola Drive/Pohakulani Street and Iwalani Street intersections. The eastbound left turn demand on Kawailani Street at Iwalani Street is expected to queue up to 150 feet. The proposed 290± foot storage lane on eastbound Kawailani Street is expected to be more than adequate to accommodate the 90 percentile left turn queue. III. Scheme B A. Year 2018 AM Peak Hour Traffic With Scheme B The proposed Scheme B traffic improvements would result in satisfactory LOS at the intersection of Kawailani Street and Ainaola Drive/Pohakulani Street. Scheme B AM peak hour traffic operations were analyzed using an 80 second traffic signal cycle length. The intersection of Kawailani Street and Iwalani Street is expected to operate at an overall LOS "C". The northbound approach of Iwalani Street is expected to operate at LOS "D". The LOS on the eastbound through movement on Kawailani Street at Iwalani Street would improve from LOS "B" under Scheme A to LOS "A" under Scheme B, resulting from the addition of two through lanes crossing the intersection. On the other hand, the LOS on the westbound through movement on Kawailani Street at Iwalani Street dropped from LOS "B" under Scheme A to LOS "C" under Scheme B, with the reduction from two through lanes to one through lane. The left turn demand on eastbound Kawailani Street at Iwalani Street is expected to occupy most of the storage length in the two-way left tum lane during the AM peak hour. The 90 percentile left tum queue on eastbound Kawailani Street is expected to extend up to 350 feet. During the Year 2018 AM peak hour of traffic, the 90 percentile left turn queue on westbound Kawailani Street at Ainaola Drive/Pohakulani Street is expected to extend up to 200 feet, utilizing only the exclusive left turn lane. The Year 2018 AM peak hour traffic with Scheme B is depicted on Figure 18. 41- Kawailani Street Improvements Traffic Impact Analysis Aineola Drive/Pohakulani Street to Iwalani Street Scheme 8 POHAKULANI STREET 6 469 Ic C 12 , 18 7 1 216 V'-�V Q KAWAILANI KAWAILANI S 1> STREET 561 9 594 10 I� 154 IWALANI STREET KAWAILANI STREET 535 {� 17 KAWAILANI STREET g 25 2j130 762 �(1D 11 AINAOLA DRIVE IWALANI STREET NOT TO SCALE LEGEND 90 TRAFFIC MOVEMENT VOLUME (VPH) \ LANE CONTROL ©� LEVEL OF SERVICE (UNSIGNALIZED CONDITION) © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 18. Year 2018 AM Peak Hour Traffic With Scheme B -42- Kawailani Street Improvements Traffic Impact Analysis Ainaola Drive/Pohakulani Street to Iwalani Street Scheme 8 B. Year 2018 PM Peak Hour Traffic With Scheme B During the PM peak hour of traffic with Scheme B improvements, the study intersections are expected to operate at LOS "C" or better. The Scheme B PM peak hour traffic operations also were analyzed using an 80 second traffic signal cycle length. Figure 19 depicts the Year 2018 PM peak hour traffic with Scheme B. The 90 percentile left turn queue on eastbound Kawailani Street at Iwalani Street is expected to extend up to 175 feet. The left tum queue on westbound Kawailani Street at Ainaola Drive/Pohakulani Street can be accommodated in the proposed double left turn lanes The westbound left turn demand is distributed among the double left turn lanes, assuming that 80 percent of the unutilized portion of the two-way left tum lane is occupied with the remaining left turn demand queuing in the exclusive left tum lane. The 90 percentile left turn queue on westbound Kawailani Street is expected to extend up to 375 feet, and should be accommodated by the proposed 400± left turn lane. The proposed geometries at the intersection of Kawailani Street and Iwalani Street may be problematic, particularly during the PM peak hour of traffic. The eastbound through lane on Kawailani Street at Iwalani Street is channelized into the exclusive left turn lane at Ainaola Drive/Pohakulani Street. This improvement would result in a "lane trap" for through traffic, i.e., through traffic would be required to merge into the right lane at Ainaola Drive/Pohakulani Street. At the same time, southbound traffic on Iwalani Street, turning right at Kawailani Street then left at Ainaola Drive, would have to merge into the left tum lane. This condition would result in weaving conflicts between the two movements in a relative short distance between the study intersections. 43- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street POHAKULANI STREET C 10 7 4 KAWAILANI STREET �4 360 39 25 449 621 cS KAWAILANI AINAOLA DRIVE STREET 1 5 289 c-jl (jam C 411 7 27 Trak Impact Analysis Scheme B IWALANI STREET i r KAWAILANI _y STREET 176 C 446 34 NOT TO SCALE 23 682 C--- B �7 32 KAWAILANI STREET 12 216 C IWALANI STREET LEGEND 90 TRAFFIC MOVEMENT VOLUME (VPH) l LANE CONTROL © LEVEL OF SERVICE (UNSIGNALIZED CONDITION) © LEVEL OF SERVICE (SIGNALIZED CONDITION) Figure 19. Year 2018 PM Peak Hour Traffic With Scheme B -44- Kawailani Street Improvements Trac Impact Analysis Ainaola Drive/Pohakulani Street to Iwalani Street Capacity Analysis Summary IV. Capacity Analysis Summary Table 2 summarizes the capacity analysis of Schemes A and B. Table 2. Analysis of Schemes A and B Kawailani Street Intersection Left Turn Lane Length Cycle Length Scheme A Scheme B Ainaola Drive/ Pohakulani Street AM Peak Hour LOS B B V/C 0.82 0.48 PM Peak Hour LOS B B V/C 0.79 0.63 Iwalani Street AM Peak Hour LOS B C V/C 0.69 0.87 PM Peak Hour LOS B B V/C 0.64 0.82 Table 3 summarizes the left queue lengths between Ainaola DrivePohakulani Street and Iwalani Street. Table 3. Left Turn Queue Length Summary Scheme Left Turn Lane Length Cycle Length EB WB A Available Lane Length N/A 290 400 AM Peak Hour 90%ile Queue 60 275 150 PM Peak Hour 90%ile Queue 60 150 400 B Available Lane Length " N/A 350 400 AM Peak Hour 90%ile Queue 80 350 200 PM Peak Hour 90%ile Queue 80 175 375 "Note: EB LT lane length includes portion of two-way left turn lane. WB LT lane length includes only full length left turn lane. -45- Kawailani Street Improvements Ainaola DriveRohakulani Street to Iwalani Street V. Pohakulani Street Traffic Assessment A. General Traffic Impact Analysis Pohakulani Street Traffic Assessment The preferred realignment options for the south leg of Pohakulani Street at Ainaola Drive are discussed in the descriptions of Alternatives 1 and 2. The objective of the realignment was to further separate the intersection of Pohakulani Street and Ainaola Drive and the intersection of Kawailani Street and Ainaola Drive. Alternative I would provide intersection spacing on Ainaola Drive between Kawailani Street and Pohakulani Street of 140± feet. Alternative 2 would provide an intersection spacing of over 400 feet. The projected PM peak hour left turn demand meets the volume warrant for an exclusive left turn lane, which was developed by M. D. Harmelink and adopted by the American Association of State Highway and Transportation Officials (AASHTO). An exclusive left tum lane on Ainaola Drive at Pohakulani Street is proposed under Scheme A only. Ainaola Drive is proposed to be widened to provide two through lanes in each direction under Scheme B. Scheme B does not provide for an exclusive left turn lane at Pohakulani Street due to right-of-way constraints. B. Scheme A Under Alternative IA, the intersection of Ainaola Drive and Pohakulani Street would be situated closer to Kawailani Street. However, an exclusive left turn would be provided to separate the left tum vehicles from through traffic. Alternative lA was previously depicted on Figure 14. Alternative 2A is the most desirable option for the proposed Pohakulani Street realignment. It would include an exclusive left tum lane on Ainaola Drive, while providing for an intersection spacing of over 400 feet from Kawailani Street. Figure 20 depicts Alternative 2A. C. Scheme B Alternative lB is the least desirable option for the proposed Pohakulani Street realignment. The intersection spacing on Ainaola Drive, between Kawailani Street and Pohakulani Street, may adversely impact traffic operations at the intersection of Kawailani Street and Ainaola Drive/Pohakulani Street. During the PM peak hour, the heavy left turn movement from westbound Kawailani Street to Ainaola Drive Alternative 2A Alternative 2B Figure 20. Pohakulani Street Alignment -a7- Kawailani Street Improvements Traffic Impact Analysis Ainaola Drive/Pohakulani Street to Iwalani Street Pohakulani Street Traffic Assessment may experience delay behind a vehicle waiting to turn left from the through lane on Ainaola Drive to Pohakulani Street. The sight distance between a motorist turning left from Kawailani Street and a vehicle waiting to turn left from the through lane on southwest bound Ainaola Drive is limited. Alternative 1 B was previously depicted on Figure 15. Alternative 2B presents the same situation as Alternative 1 B with regard to potential delays to southwest bound traffic on Ainaola Drive. However, the intersection of Pohakulani Street and Ainaola Drive would be located over 400 feet southwest of Kawailani Street. The intersection spacing would provide adequate distance for a motorist in the left lane to slow down and stop or to change lanes and bypass the vehicle waiting to turn left at Pohakulani Street. The Pohakulani Street realignment under Alternative 2B also is depicted on Figure 20. -48- Chapter 6. Recommendations and Conclusions I. Recommendations Alternative 2A is recommended for the improvements of the Kawailani Street intersections at Ainaola Drive/Pohakulani Street and at Iwalani Street. These improvements minimize the right-of-way acquisition requirements, while still provide satisfactory LOS for the design year traffic demands. A. General 1. Kawailani Street should be widened from two lane to four lanes between Iwalani Street and Ainaola Drive/Pohakulani Street. 2. An exclusive lett turn lane should be provided on Kawailani Street at the Wiki Wiki Mart driveway. B. Intersection of Ainaola Drive/Pohakulani Street and Kawailani Street 1, Traffic signals should be installed at the intersection of Ainaola Drive/ Pohakulani Street and Kawailani Street. 2. The four lane widening should provide one through lane and an exclusive left turn lane in both directions on Kawailani Street at Ainaola Drive/Pohakulani Street. 3. Ainaola Drive should be realigned to intersect Kawailani Street at a conventional right angle intersection. -49- Kawailani Street Improvements Recommendations and Conclusions Ainaola Drive/Pohakulani Street to lwalani Street Conclusions C. Intersection of Iwalani Street and Kawailani Street 1. Traffic signals should be installed at the intersection of Iwalani Street and Kawailani Street. 2. The four lane widening of Kawailani Street at Iwalani Street should provide an exclusive left turn lane and a shared through/right turn lane in the westbound direction. 3. The westbound approach of Kawailani Street at Iwalani Street should provide an exclusive left turn lane, a through only lane, and a shared through/right turn lane. 4. The north leg of Iwalani Street would be widened to provide an exclusive right turn lane in the southbound direction. D. Intersection of Pohakulani Street and Ainaola Drive 1. The existing south leg of Pohakulani Street at Ainaola Drive should be reconstructed into a cul-de-sac. Access to Pohakulani Street should be provided via a new roadway through an undeveloped lot further south on Ainaola Drive. 2. An exclusive left turn lane should be provided on southwest bound Ainaola Drive at the new access road to Pohakulani Street. 3. The new Pohakulani Street access should provide separate left turn and right turn lanes. H. Conclusions Kawailani Street, between Ainaola Drive/Pohakulani Street and Iwa)ani Street is an existing "bottleneck" during the peak hours of traffic. Traffic, turning left from eastbound Kawailani Street to northbound Iwalani Street, creates traffic queues during the AM peak hour. During the PM peak hour of traffic, the reverse situation occurs when traffic turning left from westbound Kawailani Street to southwest bound Ainaola Drive creates traffic queues. The queuing on Kawailani Street causes extreme delays to through traffic and side street traffic. In evaluating alternative improvements for Kawailani Street, a heavy emphasis was placed upon property acquisition costs, condemnation of homes, impacts to residents, and overall construction costs, The highest ranked alternatives, in terms of engineering design and traffic operations, were rated among the lowest overall. In the final analysis, 50- Kawailani Street Improvements Ainaola Drive/Pohakulani Street to Iwalani Street Recommendations and Conclusions Conclusions Alternative 2A satifies the minimum requirements for traffic operations and safety, while minimizing the environmental impacts of the proposed improvements and reducing the overall cost of the project. -51- APPENDIX 2 AIR QUALITY STUDY AIR QUALITY STUDY FOR THE PROPOSED KA W AILANI-I W ALANI-AINAO LA TRAFFIC SIGNAL IMPROVEMENTS PROJECT HILO, HAWAII Prepared for: July 1998 B. D. NEAL & ASSOCIATES Applied Meteorology • Air Quality • Computer Seieuce P.O. BOX 6239. OCEAN VIEW. HAWAII 967376239 TELEPHONE (808) 9399317 • FAX (808) 9397390 CONTENTS Section 1.0 Summary Pacre 1 2.0 Introduction and Project Description 4 3.0 Ambient Air Quality Standards 5 4.0 Regional and Local Climatology 4 5.0 Present Air Quality 10 6.0 Short -Term Impacts of Project 12 7.0 Long -Term Impacts of Project 14 8.0 Conclusions and Recommendations 27 References 30 Ficrure 1 Project Location Map FIGURES TABLES Tile 1 Summary of State of Hawaii and National Ambient Air Quality Standards 2 Air Pollution Emissions Inventory for Island of Hawaii, 1993 TABLES (cont.) 3 Estimated Worst -Case 1 -Hour Carbon Monoxide Concentrations Along Roadways Near Kawailani- Iwalani-Ainaola Traffic Signal Improvement Project 4 Estimated Worst -Case 8 -Hour Carbon Monoxide Concentrations Along Roadways Near Kawailani- Iwalani-Ainaola Traffic Signal Improvement Project 1.0 SUMMARY The County of Hawaii is proposing to improve the safety and operation of the existing roadway intersections along Kawailani Street at Ainaola Drive/Pohakulani Street and at Iwalani Street in the Waiakea area of South Hilo, Hawaii. The project will include installation of traffic signals and realigning and widening of streets near these intersections. This study examines the potential short-term and long-term air quality impacts that could occur as a result of construction and use of the proposed roadway facilities through the year 2018. Mitigative measures are suggested where possible and appropriate to lessen any potential air quality impacts from the project. Both federal and state standards have been established to maintain ambient air quality. At the present time, seven parameters are regulated including: particulate matter, sulfur dioxide, hydrogen sulfide, nitrogen dioxide, carbon monoxide, ozone and lead. Hawaii state air quality standards are more stringent than the comparable national limits except for sulfur dioxide and the recently revised national particulate matter standard. Regional and local climate together with the amount and type of human activity generally dictate the air quality of a given location. The climate of the Hilo area is very much affected by its windward and coastal situation. Daytime winds are predominantly trade winds from easterly to northerly directions, while nighttime winds are mostly mountain drainage winds from the southwest. Wind speeds typically are relatively light varying between about S and 10 miles per hour. Temperatures in the Hilo area are very moderate with average daily minimum and maximum temperatures ranging from 66°F to 82°F. Rainfall is substantial with an average of 129 inches per year. Except for occasional impacts from nearby volcanic emissions and possibly occasional localized impacts from traffic congestion, the present air quality of the project area is believed to be relatively good. The little air quality data that are available for the area from the Department of Health indicate that concentrations are currently well within state and federal air quality standards. If the proposed project is given the necessary approvals to proceed, it is probably inevitable that some short-term impacts on air quality will occur either directly or indirectly during project construction. Short-term impacts from fugitive dust may occur, and increased emissions from traffic disruption may also reduce air quality during the period of construction. State air pollution control regulations prohibit visible emissions of fugitive dust. Hence, an effective dust control plan should be implemented to ensure compliance with state regulations. 2 The high rainfall in the project area should serve to naturally control construction dust to a large extent, but it is recommended that during prolonged dry periods that active work areas be watered at least twice daily. A minimum dust control plan should also include provisions for keeping adjacent paved roadways free of tracked dirt. Increased emissions from traffic disruption can be mitigated by moving construction equipment and workers to and from the project site during off-peak traffic hours and by minimizing road closures during peak -traffic periods. After construction, the long-term impacts of emissions from motor vehicles using the improved roadways were assessed based on an air quality modeling study. The air quality modeling study was designed to estimate current worst-case ambient concentrations of carbon monoxide in the project area and to predict future levels both without and with the proposed project in the year 2018. Areas near the two primary intersections proposed for improvement were studied. These included Ainaola Drive/Pohakulani Street at Kawailani Street and Iwalani Street at Kawailani Street. The model results indicated that despite some traffic congestion during peak traffic periods present worst-case carbon monoxide concentrations are within both the national and the state standards. In the year 2018 without the project, worst-case concentrations were predicted to continue to comply with the national standards, but the worsening traffic congestion in the area could cause the state standards to be exceeded near the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street. With any of the project alternatives being contemplated 3 (1A, 2A, 1B or 2B), the model results predict that the potential exceedance of the state standards in the project area would be eliminated, i.e., the overall air quality would be better with the project than without it. Thus, measures to mitigate long-term air quality impacts of the proposed project appear to be either unnecessary or unwarranted. 2.0 INTRODUCTION AND PROJECT DESCRIPTION The County of Hawaii is proposing to improve the safety and operation of two existing intersections along Kawailani Street in the Waiakea, South Hilo, Hawaii area. These intersections are Ainaola Drive/Pohakulani Street with Kawailani Street and Iwalani Street with Kawailani Street (see Figure 1). Currently, these intersections operate at a poor level of service during peak traffic hours, and traffic projections indicate the problems will only grow worse with time unless improvements are undertaken to improve traffic flow. The proposed project includes the installation of a new traffic signal system and the realignment and widening of several streets in this area. With the proposed improvements, traffic at these intersections is expected to flow more efficiently and safely at least through the year 2018. The purpose of this study was to evaluate the potential air quality impacts of the proposed project and recommend mitigative measures, if possible and appropriate, to reduce or eliminate any degradation of air quality in the area. Before examining the 4 potential impacts of the proposed project, a discussion of ambient air quality standards is presented and background information concerning the regional and local climatology and the present air quality of the project area is provided. 3.0 AMBIENT AIR QUALITY STANDARDS Ambient concentrations of air pollution are regulated by both national and state ambient air quality standards (AAQS). National AAQS are specified in Section 40, Part 50 of the Code of Federal Regulations (CFR), while State of Hawaii AAQS are defined in Chapter 11-59 of the Hawaii Administrative Rules. Table 1 summarizes both the national and the state AAQS that are speci- fied in the cited documents. As indicated in the table, national and state AAQS have been established for particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone and lead. The state has also set a standard for hydrogen sulfide. National AAQS are stated in terms of both primary and secondary standards for most of the regulated air pollutants. National primary standards are designed to protect the public health with an "adequate margin of safety". National secondary standards, on the other hand, define levels of air quality necessary to protect the public welfare from "any known or anticipated adverse effects of a pollutant". Secondary public welfare impacts may include such effects as decreased visibility, diminished comfort levels, or other potential injury to the natural or man-made environment, e.g., soiling of materials, damage to vegetation or other econom- ic damage. In contrast to the national AAQS, Hawaii State AAQS 5 are given in terms of a single standard that is designed ,to protect public health and welfare and to prevent the significant deterioration of air quality". Each of the regulated air pollutants has the potential to create or exacerbate some form of adverse health effect or to produce environmental degradation when present in sufficiently high concentration for prolonged periods of time. The AAQS specify a maximum allowable concentration for a given air pollutant for one or more averaging times to prevent harmful effects. Averaging times vary from one hour to one year depending on the pollutant and type of exposure necessary to cause adverse effects. In the case of the short-term (i.e., 1- to 24-hour) AAQS, both national and state standards allow a specified number of exceedances each year. State of Hawaii AAQS are in some cases considerably more strin- gent than comparable national AAQS. In particular, the State of Hawaii 1 -hour AAQS for carbon monoxide is four times more strin- gent than the comparable national limit, and the state 1 -hour limit for ozone is more than two times as stringent as the national 1 -hour standard. The national 1 -hour ozone standard will be phased out during the next three years in favor of the new (and more stringent) 8 -hour standard. 9 Hawaii AAQS for sulfur dioxide were relaxed in 1986 to make the state standards essentiall-,/ the same as the national limits. In 1993, the state also revised its particulate standards to follow those set by the federal government. During 1997, the federal government again revised its standards for particulate. To date, the Hawaii Department of Health has not updated the state particulate standards. 4.0 REGIONAL AND LOCAL CLIMATOLOGY Regional and local climatology significantly affects the air quality of a given location. Wind, temperature, atmospheric turbulence, mixing height and rainfall all influence air quality. Although the climate of Hawaii is relatively moderate throughout most of the state, significant differences in these parameters may occur from one location to another. Most differences in regional and local climates within the state are caused by the mountainous topography. The entire state of Hawaii lies well within the belt of northeast- erly trade winds generated by the semi-permanent Pacific high pressure cell to the north and east of the islands. Areas along the eastern coasts of the islands are particularly affected by the trade winds and are usually well -ventilated nearly year round. Although Hilo is situated along the eastern coast of Hawaii Island, the high mountains of Mauna Loa and Mauna Kea significantly modify the trade wind influence, causing winds to be 7 lighter than might be expected. The nearest long-term wind data available for the project area are collected at the Hilo Airport located about 3 miles to the east. These data are probably at least semi -representative of the project corridor. Mean annual wind speed at the airport is about 8 mph, which is lower than many windward locations in the state, and wind directions are bimodal showing either a northeast or southwest preference [1]. Northeast trade winds typically occur during the daytime, while winds from the southwest typically occur during the nighttime due to cold air drainage from the mountains. winds from the south or southwest also occur occasionally in association with winter storms. Air pollution emissions from motor vehicles, the formation of photochemical smog and smoke plume rise all depend in part on air temperature. Colder temperatures tend to result in higher emissions of contaminants from automobiles but lower concentrations of photochemical smog and ground -level concentra- tions of air pollution from stack sources. In Hawaii, the annual and daily variation of temperature depends to a large degree on elevation above sea level, distance inland and exposure to the trade winds. Average temperatures at locations near sea level generally are warmer than those at higher elevations. Areas exposed to the trade winds tend to have the least temperature variation, while inland and leeward areas often have the most. At nearby Hilo Airport, average annual daily minimum and maximum temperatures are 66°F and 82°F, respectively. The extreme minimum temperature on record is 53°F, and the extreme maximum is 8 94°F [2]. Temperatures in the project vicinity are probably very similar. Small scale, random motions in the atmosphere (turbulence) cause air pollutants to be dispersed as a function of distance or time from the point of emission. Turbulence is caused by both mechan- ical and thermal forces in the atmosphere. It is oftentimes measured and described in terms of Pasquill-Gif ford stability class. Stability class 1 is the most turbulent and class 6 the least. Thus, air pollution dissipates the best during stability class 1 conditions and the worst when stability class 6 prevails. In the project area, stability class 5 or 6 is probably the highest stability class that occurs, developing during clear, calm nighttime or early morning hours when temperature inversions form due to radiational cooling. Stability classes 1 through 4 occur during the daytime, depending mainly on the amount of cloud cover and incoming solar radiation and the onset and extent of the sea breeze. Mixing height is defined as the height above the surface through which relatively vigorous vertical mixing occurs. Low mixing heights can result in high ground -level air pollution concentra- tions because contaminants emitted from or near the surface can become trapped within the mixing layer. In Hawaii, minimum mixing heights tend to be high because of mechanical mixing caused by the trade winds and because of the temperature moderating effect of the surrounding ocean. Low mixing heights 0 may sometimes occur, however, at inland locations and even at times along coastal areas early in the morning following a clear, cool, windless night. Coastal areas also may experience low mixing levels during sea breeze conditions when cooler ocean air rushes in over warmer land. Mixing heights at most locations in Hawaii typically are above 3000 feet (1000 meters). Rainfall can have a beneficial affect on the air quality of an area in that it helps to suppress fugitive dust emissions, and it also may "washout" gaseous contaminants that are water soluble. Rainfall in Hawaii is highly variable depending on elevation and on location with respect to the trade wind. The Hilo area has a wet climate. Normal annual rainfall for Hilo Airport is about 129 inches (2]. This is distributed fairly evenly throughout the year, although the summer months are slightly drier. 5.0 PRESENT AIR QUALITY Air quality in the vicinity of the proposed project is currently mostly affected by emissions from motor vehicles, industry and natural sources. Table 3 presents an air pollutant emission summary for the island of Hawaii for calendar year 1993. The emission rates shown in the table pertain to manmade emissions only, i.e., emissions from natural sources are not included. As suggested in the table, much of the manmade particulate, sulfur oxides and hydrocarbon emissions on Hawaii Island originate from point sources, such as power plants and other fuel -burning E industries. Area sources of particulate emissions include the mineral products industry and agriculture. Nitrogen oxides and carbon monoxide emissions emanate predominantly from area sources, i.e., motor vehicle traffic. Although not included in the emissions inventory, perhaps the dominant air pollutant emission source on the island for the past several years has been the Kilauea Volcano, but the trade winds carry volcanic emissions away from the Hilo area much of the time. Most of the volcanic emissions occur as sulfur dioxide and then convert into particulate sulfate which causes a volcanic haze (vog) to blanket the area during kona wind conditions. The major industrial sources in the Hilo area specifically are oil -burning power plants which primarily emit sulfur dioxide, nitrogen oxides and particulate matter. Local motor vehicle traffic emits carbon monoxide, nitrogen oxides, particulate, hydrocarbons (an ozone precursor) and smaller amounts of other pollutants. The State Department of Health (DOH) operates a network of air quality monitoring stations at various locations around the state. Each station, however, typically does not monitor the full complement of air quality parameters. Very little data have been reported for the Hilo area. During 1985, DOH collected samples of 24-hour average particulate matter and sulfur dioxide concentra- tions at the University of Hawaii -Hilo campus (3). These data indicated that concentrations were well within standards, and monitoring was discontinued. Other data have been collected and reported since 1985 in connection with electrical power development in Hilo and Puna, but these data have not been published to date by DOH. Although there are no air quality data to substantiate this, it is probable that the more stringent state standards pertaining to carbon monoxide are exceeded on occasion near high-volume intersections in the Hilo area during periods of coincident traffic congestion and poor dispersion conditions. 6.0 SHORT-TERM IMPACTS OF PROJECT Short-term direct and indirect impacts on air quality could potentially occur during project construction. For a project of this nature, there are two potential types of air pollution emissions that could directly result in short-term air quality impacts during project construction: (1) fugitive dust from vehicle movement and soil excavation; and (2) exhaust emissions from on-site construction equipment. Indirectly, there also could be short-term impacts from slow-moving construction equipment traveling to and from the project site and from the disruption of normal traffic flow caused by roadway closures. Fugitive dust emissions may arise from the grading and dirt -moving activities associated with site clearing and preparation work. The emission rate for fugitive dust emissions from construction activities is difficult to estimate accurately 12 because of its elusive nature of emission and because the potential for its generation varies greatly depending upon the type of soil at the construction site, the amount and type of dirt -disturbing activity taking place, the moisture content of exposed soil in work areas, and the wind speed. The EPA (4] has provided a rough estimate for uncontrolled fugitive dust emissions from construction activity of 1.2 tons per acre per month under conditions of "medium" activity, moderate soil silt content (30%), and precipitation/evaporation (P/E) index of 50. Uncontrolled fugitive dust emissions in the project area would likely be lower due to the wet climate. In any case, State of Hawaii Air Pollution Control Regulations (5] prohibit visible emissions of fugitive dust from construction activities at the property line. Thus, an effective dust control plan for the project construction phase is essential. Adequate fugitive dust control can usually be accomplished by the establishment of a frequent watering program to keep bare -dirt surfaces in construction areas from becoming significant sources of dust. In dust -prone or dust -sensitive areas, other control measures such as limiting the area that can be disturbed at any given time, applying chemical soil stabilizers, mulching and/or using wind screens may be necessary. Control regulations further stipulate that open -bodied trucks be covered at all times when in motion if they are transporting materials that could be blown away. Haul trucks tracking dirt onto paved streets from unpaved areas is oftentimes a significant source of dust in construction 13 areas. Some means to alleviate this problem, such as road cleaning or tire washing, may be appropriate. On-site mobile and stationary construction equipment also will emit air pollutants from engine exhausts. The largest of this equipment is usually diesel -powered. Nitrogen oxides emissions from diesel engines can be relatively high compared to gasoline - powered equipment, but the standard for nitrogen dioxide is set on an annual basis and is not likely to be violated by short-term construction equipment emissions. Carbon monoxide emissions from diesel engines, on the other hand, are low and should be relatively insignificant compared to vehicular emissions on nearby roadways. Project construction activities will also likely obstruct the normal flow of traffic at times to such an extent that overall vehicular emissions in the project area will temporarily increase. The only means to alleviate this problem will be to attempt to keep roadways open during peak traffic hours and to move heavy construction equipment to and from construction areas during periods of low traffic volume. 7.0 LONG-TERM IMPACTS OF PROJECT After construction is completed, use of the proposed new facilities could potentially cause long-term impacts on ambient 14 air quality in the project vicinity if it causes an increase in motor vehicle emissions or if it concentrates more traffic near the affected intersections. It is not anticipated that the project will result in higher traffic volumes, but the widening of roadways and the installation of traffic signals may increase motor vehicle emissions near the modified intersections. Motor vehicles with gasoline -powered engines are significant sources of carbon monoxide, and they also emit nitrogen oxides and other contaminants. Federal air pollution control regulations require that new motor vehicles be equipped with emission control devices that reduce emissions significantly compared to a few years ago. In 1990, the President signed into law the Clean Air Act Amendments. This new legislation required further emission reductions be phased in beginning in 1994. The combination of current and new restrictions on emissions from new motor vehicles will lower average emissions each year as more and more older vehicles leave the state's roadways. Carbon monoxide emissions, for example, are expected to decrease by about 20 to 30 percent on the average during the next 20 years due to the replacement of older vehicles with newer models. To evaluate the potential long-term ambient air quality impact of a project such as this, computerized emission and atmospheric dispersion models can be used to estimate ambient carbon monoxide concentrations along the affected roadways. Carbon monoxide is 15 selected for modeling because it is both the most stable and the most abundant of the pollutants generated by motor vehicles. Furthermore, carbon monoxide air pollution is generally considered to be a microscale problem that can be addressed locally to some extent, whereas nitrogen oxides air pollution most often is a regional issue that cannot be addressed by a single roadway improvement. For this project, four scenarios were selected for the carbon monoxide modeling study: year 1997 with present conditions, year 2018 without the project, year 2018 with project Alternative lA or 2A and year 2018 with project Alternative 1B or 2B. Presently, the intersections of Kawailani Street with Iwalani Street and with Pohakulani Street/Ainaola Drive are two-way stop - controlled with Kawailani Street being the major (unstopped) roadway, and it is assumed these intersections would remain unchanged in the 2018 without project scenario. The with project alternatives are described in the project traffic study (6) and elsewhere in more detail, but briefly, all project alternatives include the widening and signalization of the two intersections. All four project alternatives also include the realignment of Pohakulani Street with Ainaola Drive. The primary difference between Alternatives 1A/2A and 1B/2B with respect to the Kawailani intersections is the laneage along Kawailani Street. In Alternatives 1A/2A, Kawailani Street at Pohakulani Street/Ainaola Drive would have only one left -turn lane for westbound traffic whereas in Alternatives 1B/2B, two left -turn lanes would be provided. In Alternatives 1A/2A, Kawailani Street E. at Iwalani Street would have two lanes for westbound through traffic and one lane for eastbound through traffic; in Alternatives 1B/2B, the laneage for eastbound/westbound through traffic would be reversed, i.e., one lane for westbound through traffic and two lanes for eastbound through traffic. The main objective of the carbon monoxide modeling study was to estimate maximum 1 -hour average concentrations for each of the four scenarios studied. To evaluate the significance of the estimated concentrations, a comparison of the predicted values for each scenario can be made. Comparison of the estimated values to the national and state AAQS will provide another measure of significance. The traffic impact report for the project indicates that traffic volumes will be slightly higher during the morning peak hour than during the afternoon peak period. Coincidentally, worst-case emission and meteorological dispersion conditions typically occur during the morning hours at most locations. Thus, the highest concentrations could be expected to occur during the morning peak traffic period. However, to ensure that there were no unusual traffic queuing conditions during the afternoon and that worst- case concentrations were identified, both morning and afternoon peak -traffic hours were examined for each scenario. 17 The EPA computer model MOBILESA [7) was used to calculate vehicular carbon monoxide emissions for each year studied. This model is the most recently released version of the EPA mobile emission models. Emission estimates provided by the MOBILESA model have been updated based on EPA's recent testing of on -road vehicles. This latest series of tests has indicated that emission control equipment deteriorates more rapidly than had been previously thought. Hence, MOBILESA emission estimates are higher (in some cases as much as twice as high) compared to emission estimates derived from earlier versions of the model, particularly in states like Hawaii that have no inspection and maintenance program for emission control equipment. The EPA computer model MOBILESA was used to calculate vehicular carbon monoxide emissions for each year studied. One of the key inputs to MOBILESA is vehicle mix. Unless very detailed information is available, national average values are typically assumed, which is what was used for the present study. Based on national average vehicle mix figures, the projected vehicle mix in the project area for 1997 was estimated to be 62.5% light-duty gasoline -powered automobiles, 27.01k light-duty gasoline -powered trucks and vans, 3.1% heavy-duty gasoline -powered vehicles, 0.316 light-duty diesel -powered vehicles, 6.4% heavy-duty diesel -powered trucks and buses, and 0.7% motorcycles. For the future scenarios studied, the estimated national average vehicle mix percentages were substantially the same except that light-duty gasoline - powered automobiles decreased by about 5% while light-duty 18 gasoline -powered trucks and vans increased by about the same amount. Other key inputs to the MOBILESA emission model are the cold/hot start fractions. Motor vehicles operating in a cold- or hot -start mode emit excess air pollution. Typically, motor vehicles reach stabilized operating temperatures after about 4 miles of driving. For traffic operating within the project area, it was assumed that about 21 percent of all vehicles would be operating in the cold - start mode and that about 27 percent would be operating in the hot -start mode. These are typical default (national average) values. Ambient temperatures of 59 and 68 degrees Fahrenheit were used for morning and afternoon peak -hour emission computations, respectively. These are conservative assumptions since morning/afternoon ambient temperatures will generally be warmer than this and emission estimates given by MOBILE5A are inversely proportional to the ambient temperature. After computing vehicular carbon monoxide emissions through the use of MOBILE5A, these data were then input to an atmospheric dispersion model. EPA air quality modeling guidelines (8] currently recommend that the computer model CAL3QHC [9] be used to assess carbon monoxide concentrations at roadway intersections, or in areas where its use has previously been 19 established, CALINE4 [10] may be used. Until recently, CALINE4 was used extensively in Hawaii to assess air quality impacts at roadway intersections. However, in December 1997, the California Department of Transportation recommended that the intersection mode of CALINE4 no longer be used because it was thought the model has become outdated. Studies have shown that CALINE4 may tend to over -predict maximum concentrations in some situations. Because of the recent recommendation by the California Department of Transportation that the intersection mode of CALINE4 no longer be used, CAL3QHC was used for the subject analysis. CAL3QHC was developed for the U.S. EPA to simulate vehicular movement, vehicle queuing and atmospheric dispersion of vehicular emissions near roadway intersections. It is designed to predict 1 -hour average pollutant concentrations near roadway intersections based on input traffic and emission data, roadway/receptor geometry and meteorological conditions. Input peak -hour traffic data were obtained from the traffic study cited previously. This included vehicle approach volumes, saturation capacity estimates, intersection laneage and signal timings. For the future signalized intersection scenarios, all emission factors that were input to CAL3QHC for free-flow traffic were obtained from MOBILESA based on an assumed free-flow vehicle speed of 30 mph. There is no specific methodology for applying CAL3QHC to unsignalized intersections, but it was assumed that free-flow speeds for each approach would be related to the reserve 20 volume/capacity ratio. A base free-flow speed of 15 mph was assumed for the stop -controlled approaches, and this was adjusted downward based on the reserve volume/capacity ratio of the approach to a minimum of 2.5 mph. A free-flow speed of 30 mph was assumed for the non-stop approaches, and this was adjusted downward based on the left -turn reserve volume/capacity ratio, also to a minimum of 2.5 mph. Model roadways were set up to reflect roadway geometry, physical dimensions and operating characteristics. Concentrations predicted by air quality models generally are not considered valid within the roadway mixing zone. The roadway mixing zone is usually taken to include 3 meters on either side of the traveled portion of the roadway and the turbulent area within 10 meters of a cross street. For this study, model receptor sites were located at the edges of the mixing zones where the maximum concentrations would likely occur, whether or not sidewalks currently exist. All receptor heights were placed at 1.8 meters above ground to simulate levels within the normal human breathing zone. Input meteorological conditions for this study were defined to provide "worst-case" results. One of the key meteorological inputs is atmospheric stability category. For these analyses, atmospheric stability category 5 was assumed for morning scenarios and stability category 4 was assumed for afternoon cases. These are the most conservative stability categories that 21 are generally used for estimating worst-case pollutant dispersion at suburban locations. A surface roughness length of 100 cm and a mixing height of 300 meters was used in all cases. Worst-case wind conditions were defined as a wind speed of 1 meter per second with a wind direction resulting in the highest predicted concentration. Concentration estimates were calculated at wind directions of every 5 degrees. Existing background concentrations of carbon monoxide in the project vicinity are believed to be at relatively low levels. Hence, background contributions of carbon monoxide from sources or distant roadways not directly considered in the analysis were accounted for by adding a small background concentration of 0.5 ppm to all predicted concentrations for 1997. At least moderate development and increased traffic are expected to occur in the project area within the next several years which may result in an increase in background concentrations, although some of this will be offset by the retirement of older, more -polluting motor vehicles as discussed earlier. For the future (2018) scenarios studied, a background carbon monoxide concentration of 1 ppm was assumed. Table 3 summarizes the final results of the modeling study in the form of the estimated worst-case 1 -hour morning and afternoon ambient carbon monoxide concentrations for the two intersections 22 studied. Estimated worst-case carbon monoxide concentrations are presented in the table for the year 1997 with existing traffic, year 2018 without the project, year 2018 with project Alternatives 1A/2A and year 2018 with project Alternatives 1B/2B. The locations of these estimated worst-case 1 -hour concentrations all occurred at or very near the indicated intersections. As indicated in the table, the highest estimated 1 -hour concentration within the project vicinity for the present (1997) case was 7.5 mg/m'. This was projected to occur during the afternoon peak hour at the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street and was mainly attributable to westbound traffic on Kawailani Street. The next highest predicted concentration was 6.9 mg/m' during the morning peak traffic hour at the same intersection and was mainly attributable to northbound traffic on Pohakulani Street/Ainaola Drive. Predicted worst-case 1 -hour concentrations near the intersection of Iwalani Street and Kawailani Street were somewhat lower, ranging from 5.0 mg/m' during the morning peak hour to 6.0 mg/m' during the afternoon peak hour. All estimated worst- case 1 -hour concentrations are within both the national standard of 40 mg/m' and the more stringent state limit of 10 mg/m'. In the year 2018 without the proposed project, the predicted worst-case 1 -hour concentrations in the project area increased substantially compared to the existing case. The highest worst- case 1 -hour concentration, 13.7 mg/m', was predicted to occur 23 during the afternoon near the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street. The majority of this concentration is attributable to westbound traffic on Kawailani Street which the traffic report forecasts will experience poor level of service conditions. Worst-case concentrations during the morning at this location were predicted to be somewhat lower at 9.3 mg/m'. Worst-case concentrations near the intersection of Iwalani Street and Kawailani Street were predicted to range between 6.0 and 6.6 mg/m'. All predicted worst-case 1 -hour concentrations for this scenario are within both the national and the state AAQS except for the afternoon period near the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street which exceeds the state AAQS. Predicted 1 -hour worst-case concentrations for the 2018 with project Alternatives 1A/2A scenario ranged from 5.4 mg/m' during the afternoon at the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street to 7.0 mg/m' during the morning at Iwalani Street and Kawailani Street. Compared to the without project case, predicted worst-case concentrations increased slightly or remained about the same at Iwalani Street/Kawailani Street and decreased substantially near Pohakulani Street/Ainaola Drive/Kawailani Street. All of the predicted worst-case 1 -hour concentrations for this scenario met both the state and the national AAQS. 24 Predicted 1 -hour worst-case concentrations for the 2018 with project Alternatives 1B/23 case ranged from 5.8 mg/m' during the afternoon at the intersection of Iwalani Street and Kawailani Street to 7.5 mg/m' during the morning at Pohakulani Street/Ainaola Drive and Kawailani Street. The predicted concentrations were substantially the same as for the Alternatives 1A/2A scenario with all of the predicted worst-case 1 -hour concentrations meeting both the state and the national AAQS. Worst-case 8 -hour carbon monoxide concentrations were estimated by multiplying the worst-case 1 -hour values by a persistence factor of 0.5. This accounts for two factors: (1) traffic volumes averaged over eight hours are lower than peak 1 -hour values, and (2) meteorological dispersion conditions are more variable (and hence more favorable) over an 8 -hour period than they are for a single hour. Based on monitoring data, 1 -hour to 8 -hour persistence factors for most locations generally vary from 0.4 to 0.8 with 0.6 being the most typical. One recent study based on modeling [ill concluded that 1 -hour to 8 -hour persistence factors could typically be expected to range from 0.4 to O.S. EPA guidelines [12] recommend using a value of 0.6 to 0.7 unless a locally derived persistence factor is available. Monitoring data for Honolulu reported by the Department of Health suggest that this factor may range between about 0.35 and 0.55 depending on location and traffic variability. Considering the 25 location of the project and the traffic pattern for the area, a 1 -hour to 8 -hour persistence factor of 0.5 will likely yield reasonable estimates of worst-case 8 -hour concentrations. The resulting estimated worst-case 8 -hour concentrations are indicated in Table 4. For the 1997 scenario, the estimated worst-case 8 -hour carbon monoxide concentrations were 3.8 mg/m' near the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street and 3.0 mg/m' near Iwalani Street and Kawailani Street. These are in compliance with both the state standard of 5 mg/m' and the national limit of 10 mg/m'. Without the project in the year 2018, the worst-case concentration was predicted to increase to 6.8 mg/m' near the intersection of Pohakulani Street/Ainaola Drive and Kawailani Street, which would remain in compliance with the national standard but exceed the state limit. The concentration at Iwalani Street/Kawailani Street was predicted to remain within both standards, increasing only slightly to 3.3 mg/m'. With either of the with -project alternatives studied, the maximum 8 -hour concentrations in the year 2018 were estimated to remain at about the existing levels. The results of this study reflect several assumptions that were made concerning both traffic movement and worst-case meteor- ological conditions. One such assumption concerning worst-case 1 -hour meteorological conditions is that a wind speed of 1 meter OV per second with a steady direction for one hour will occur. A steady wind of 1 meter per second blowing from a single direction for an hour is extremely unlikely and may occur only once a year or less. With wind speeds of 2 meters per second, for example, computed carbon monoxide concentrations would be only about half the values given above. The 8 -hour estimates are also conservative and are probably less reliable than the 1 -hour estimates due to the methodology used to compute the estimates. Further, it is unlikely that anyone would occupy the assumed receptor sites (within 3 m of the roadways) for a period of 8 hours. 8.0 CONCLUSIONS AND RECOMMENDATIONS Although very little ambient air quality data are available to characterize existing conditions, it is likely that state and federal ambient air quality standards are currently being met in the project area, except perhaps for occasional exceedances of the state carbon monoxide standards within small "hot -spot" areas near traffic -congested intersections. If not controlled properly, fugitive dust emissions during project construction could have a temporary impact on the air quality of areas adjacent to the project. Uncontrolled fugitive dust emissions from construction activities are estimated to amount to about 1.2 tons per acre per month or more, depending on rainfall. However, because the project area has a relatively wet 27 climate and the winds are typically relatively light, dust emissions will be naturally mitigated. During dry periods, it may be necessary to water active work areas at least twice daily to control dust. Dirt -hauling trucks should be covered when traveling on roadways to prevent windage. A routine road cleaning and/or tire washing program will also help to reduce fugitive dust emissions that may occur as a result of trucks tracking dirt onto paved roadways in the project area. During construction phases, emissions from engine exhausts (primarily consisting of carbon monoxide and nitrogen oxides) will also occur from on-site construction equipment, from vehicles used by construction workers, from trucks traveling to and from the project area and from road work which disrupts the normal flow of traffic. Increased vehicular emissions due to disruption of traffic by construction equipment and/or commuting construction workers can be alleviated by moving equipment and personnel to the site during off-peak traffic hours. Increased vehicular emissions due to the disruption of traffic can be mitigated by minimizing road closures during peak traffic hours. After construction, emissions from motor vehicle traffic using the proposed roadway improvements will occur on a long-term basis. Motor vehicle related emissions of carbon monoxide are the greatest concern. Based on the projected peak -hour traffic volumes and the roadway configurations and laneages given for the roadway intersections affected by the project, air quality model 28 projections for the year 2018 indicate that on a microscale level overall air quality conditions in the project area will benefit from the project. Without the project, worst-case concentrations in the year 2018 may meet the national standards but may exceed the more stringent state standards near the intersection of Pohakulani Street/Ainaola Drive/Kawailani Street. With the project, compliance with both state and national standards will likely be achieved and air quality levels comparable to existing conditions will likely be maintained. Thus, measures to mitigate any long-term air quality impacts of the project appear to be either unnecessary or unwarranted. �FE REFERENCES 1. Atlas of Hawaii, Second Edition, Department of Geography, University of Hawaii, University of Hawaii Press, Honolulu, 1983. 2. "Local Climatological Data, Annual Summary With Comparative Data, Hilo, Hawaii, 199311, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Envi- ronmental Data Service, National Climatic Center, Asheville, NC. 3. Hawaii Air O ual i y Data for the Period of Tan ua y1g85`to December 1987, State of Hawaii Department of Health. 4. Compilation of Air PnIlutant FmisSjon Fa c,ra Volum Stationary Point and Area Sources. Fifth di ion, AP -42, U.S. Environmental Protection Agency, Research Triangle Park, NC, January 1995. 5. State of Hawaii. Hawaii Administrative Rules, Chapter 11-60, Air Pollution Control. 6. The Traffic Management Consultant, Draft- Traffic Impact Assessment Renort for the Kawailan; I lan; Ainanla Traffir Signal Imorovem n s Project, July 1998. 7. User's Guide to MOBI Fa 1 (Mobilo SQurrP Emission Fact= Mod 1) including MOBI 5A loda e, EPA-AA-TEB-91-01, U.S. Environmental Protection Agency, Office of Air and Radiation, Office of Mobile Sources, Emission Control Technology Division, Test and Evaluation Branch, Ann Arbor, Michigan, July 1991. 8. Guideline on Air Ouality Mod is (Revised), Includina Supplements A and B, EPA -450/2-78-027R, U.S. Environmental Protection Agency, Research Triangle Park, NC, July 1986. Guide9. IJc;prlq to (AT,I()HC Version 2 -Oa A y••- •• y- 1••• ••r 10. CAT_,INE4 - A Disnersion Model forPredicting Air Pollutant- Concentrations oll antCon- ntra ions Near Roadways, FHWA/CA/TL-84/15, California State Department of Transportation, November 1984 with June 1989 Revisions. 11. "Persistence Factors for Mobile Source (Roadway) Carbon Monoxide Modeling", C. David Cooper, Journal of the Air & Waste Management Association, Volume 39, Number 5, May 1989. 12. Uuideline for Mod ling Carbon Monoxide f rQM Roadwa Tntergect ions, U.S. Environmental Protection Agency, EPA -454/R-92-005, November 1992. 31 )19 Figure I - PROJECT LOCATION v Puu loans r� Man tPil 11 Point oHilo Bres atm Point? Onekahalmha Park fBlo Bay Kaulainaimi Island i Park n Park to Waiakca Fomt Hilo Intcmatioml And 15 L Table 1 SUMMARY OF STATE OF HAWAII AND NATIONAL AMBIENT AIR QUALITY STANDARDS a Three-year average of annual arithmetic mean. b99th percentile value averaged over three years. cNot to be exceeded more than once per year. d98th percentile value averaged over three years. eThree-year average of fourth -highest daily 8 -hour maximum. fStandard is attained when the expected number of exceedances is less than or equal to 1. Maximum Allowable Concentration Pollutant Units Averaging National National State Time Primary Secondary of Hawaii Particulate Matter µg/m3 Annual 50' S0' S0 (<10 microns) 24 Hours 150° 150° 150` Particulate Matter µg/m3 Annual 15' 15' - (<2.5 microns) 24 Hours 65" 65" - Sulfur Dioxide µg/m3 Annual 80 - 80 24 Hours 365` - 365< 3 Hours - 1300` 1300` Nitrogen Dioxide µg/m3 Annual 100 100 70 Carbon Monoxide mg/m3 8 Hours 10` - 5` 1 Hour 40` - lo` Ozone µg/m3 8 Hours 157' 157' - 1 Hour 2351 235' loo` Lead µg/m3 Calendar 1.5 1.5 1.5 Quarter Hydrogen Sulfide µg/m3 1 Hour - - 35` a Three-year average of annual arithmetic mean. b99th percentile value averaged over three years. cNot to be exceeded more than once per year. d98th percentile value averaged over three years. eThree-year average of fourth -highest daily 8 -hour maximum. fStandard is attained when the expected number of exceedances is less than or equal to 1. Table 2 AIR POLLUTION EMISSIONS INVENTORY FOR ISLAND OF HAWAII, 1993 Air Pollutant 'Point Sources (tons/year) -Area-Sources (tons/year) '(tons/year) Particulate 30,311 9,157 39,468 Sulfur Oxides 9,346 nil 9,346 Nitrogen Oxides 4,054 8,858 12,912 Carbon Monoxide 3,357 23,934 27,291 Hydrocarbons 1,478 203 1,681 Source: Final Report, "Review, Revise and Update of the Hawaii Emissions Inventory Systems for the State of Hawaii", prepared for Hawaii Department of Health by J.L. Shoemaker & Associates, Inc., 1996 N m L Iq $ a) a ro T m H $$4 > o a •.� N k b L _ m L y r i N U d ' T 0 rl it i oa .j NA , q0 O it I� 10 rte{'_-• a '- m U L; . to $4 O O T T � N m - N : '~ 3. Vic. a .41 r m ' m C, o �' sa u� �o Y ti L 1i W H W -,4 1 Irs3 u m y >V) - sroi ro y V m ra ❑ • rClro ra r 41 q m x o to ro a N d X W Q M z 0 H �yF M Q O uz ° H F u � N N � a • 0 d L 70C H u pyo U " 0 0 N WOO Q H w m M 01 m 13 m ca F O^ C v PC a: H 0O O p0 H '^ H F m ea m N ym ri v T 0 rm F° ? N m o d N . y tl +i FI 3 m y a N y U T 0 > u N O d N n M re y 0 O M DCL Y Ogg y.:. a n o Of X . a+ 01 O Y Of m n n a. d ro W W m .H N ,..b. m m •ti C O •.i o w m % reb a a a . C ro X O H + (ardro ro (a 3 L C 3 31 0 ro X Q APPENDIX 3 ACOUSTIC STUDY ACOUSTIC STUDY FOR THE KAWAILANI—IWALANI—AINAOLA TRAFFIC SIGNAL IMPROVEMENTS PROJECT HILO, HAWAII Prepared for: OKAHARA & ASSOCIATES INC. Prepared by: Y. EBISU & ASSOCIATES 1126 12th Avenue, Room 305 Honolulu, Hawaii 96816 JULY 1998 TABLE OF CONTENTS CHAPTER CHAPTER TITLE PAGE NO. List of Figures List of Tables "' I. SUMMARY................................................................................... 1 II. GENERAL STUDY METHODOLOGY Noise Measurements............................................................. 3 Traffic Noise Predictions........................................................ 3 Impact Assessments and Mitigation ...................................... 8 III. EXISTING ACOUSTICAL ENVIRONMENT ................................. 14 IV. DESCRIPTION OF FUTURE TRAFFIC NOISE LEVELS .......... 22 V. POSSIBLE NOISE MITIGATION MEASURES ........................... 33 VI. FUTURE TRAFFIC NOISE IMPACTS AND RECOMMENDED NOISE MITIGATION MEASURES... ...................................... 35 VII. CONSTRUCTION NOISE IMPACTS ........................................... 44 APPENDIX A. REFERENCES.............................................................................. 48 B. EXCERPTS FROM EPA'S ACOUSTIC TERMINOLOGY GUIDE.. 49 C. SUMMARY OF BASE YEAR AND FUTURE YEAR TRAFFIC VOLUMES......................................................................... 52 Page A (i i' in, I r NUMBER 1 LIST OF FIGURES FIGURE TITLE LOCATIONS OF NOISE MEASUREMENT SITES ................. 2 HOURLY VARIATIONS OF TRAFFIC NOISE AT 100 FT SETBACK DISTANCE FROM THE CENTERLINE OF KAWAILANI STREET WEST OF IWALANI STREET .......... 3 HOURLY VARIATIONS OF TRAFFIC NOISE AT 100 FT SETBACK DISTANCE FROM THE CENTERLINE OF KAWAILANI STREET EAST OF IWALANI STREET .......... 4 HOURLY VARIATIONS OF TRAFFIC NOISE AT 100 FT SETBACK DISTANCE FROM THE CENTERLINE OF IWALANI STREET NORTH OF KAWAILANI STREET ....... 5 LOCATIONS OF NOISE SENSITIVE RECEPTORS #1 THRU #15..................................................................... PAGE NO. 6 LOCATIONS OF RECOMMENDED NOISE BARRIERS ALONG KAWAILANI STREET FOR ALTERNATIVES 1AAND 2A............................................................................. 7 LOCATIONS OF RECOMMENDED NOISE BARRIERS ALONG KAWAILANI STREET FOR ALTERNATIVES 1 B AND 2B............................................................................ D 0 10 11 12 LOCATIONS OF RECOMMENDED NOISE BARRIER ALONG AINAOLA DRIVE FOR ALTERNATIVE 1A ......... LOCATIONS OF RECOMMENDED NOISE BARRIERS ALONG AINAOLA DRIVE FOR ALTERNATIVE 2A ........... LOCATIONS OF RECOMMENDED NOISE BARRIERS ALONG AINAOLA DRIVE FOR ALTERNATIVE 16 ......... LOCATIONS OF RECOMMENDED NOISE BARRIERS ALONG AINAOLA DRIVE FOR ALTERNATIVE 2B .......... CONSTRUCTION NOISE LEVELS VS. DISTANCE .............. Page A I !`.� t, 4 9 10 11 28 37 38 39 40 41 42 45 LIST OF TABLES NUMBER TABLE TITLE PAGE NO. 1 TRAFFIC NOISE MEASUREMENT RESULTS ........................... 5 2 FHWA NOISE ABATEMENT CRITERIA ..................................... 12 3A EXISTING (CY 1997) TRAFFIC VOLUMES AND NOISE LEVELS ALONG ROADWAYS IN PROJECT AREA (AM PEAK HOUR)................................................................ 15 3B EXISTING (CY 1997) TRAFFIC VOLUMES AND NOISE LEVELS ALONG ROADWAYS IN PROJECT AREA (PM PEAK HOUR)................................................................ 16 3C IDENTIFICATION OF KAWAILANI STREET ROADWAY SEGMENTS............................................................................ 17 4A EXISTING CONDITIONS; YEAR 1997; AM PEAK HR. SETBACK DISTANCES........................................................ 18 46 EXISTING CONDITIONS; YEAR 1997; PM PEAK HR. SETBACK DISTANCES........................................................ 19 5 LIST OF NOISE IMPACTED STRUCTURES AND LAND AREAS DURING BASE YEAR (CY 1997) ......................... 20 6A NO BUILD CONDITIONS; YEAR 2018; AM PEAK HR. SETBACK DISTANCES........................................................ 23 66 NO BUILD CONDITIONS; YEAR 2018; PM PEAK HR. SETBACK DISTANCES........................................................ 24 7 LIST OF NOISE IMPACTED STRUCTURES AND LAND AREAS IN CY 2018 UNDER NO—BUILD ALTERNATIVE. 25 BA FUTURE (CY 2018) TRAFFIC VOLUMES AND NOISE LEVELS ALONG ROADWAYS IN PROJECT AREA (AM PEAK HOUR)................................................................ 26 Page 1 1 LIST OF TABLES (CONTINUED) NUMBER TABLE TITLE PAGE NO. 86 FUTURE (CY 2018) TRAFFIC VOLUMES AND NOISE LEVELS ALONG ROADWAYS IN PROJECT AREA (PM PEAK HOUR)................................................................ 27 9A SUMMARY OF EXISTING AND PREDICTED TRAFFIC NOISE LEVELS AT NOISE SENSITIVE RECEPTOR LOCATIONS #1 THRU #15 (4.92 FT. RECEPTOR, AM PEAK HOUR)................................................................. 30 9B SUMMARY OF EXISTING AND PREDICTED TRAFFIC NOISE LEVELS AT NOISE SENSITIVE RECEPTOR LOCATIONS #1 THRU #15 (4.92 FT. RECEPTOR, PMPEAK HOUR)................................................................. 31 10 PREDICTED TRAFFIC NOISE ATTENUATION VS. BARRIER HEIGHTS (4.92 FT. RECEPTOR, AM OR PM PEAK HOUR)................................................................................... 36 11 AVAILABLE WORK HOURS UNDER DOH PERMIT PROCEDURES FOR CONSTRUCTION NOISE ................. 46 Page 1 U CHAPTER I. SUMMARY The existing and future traffic noise levels along in the environs of the proposed Kawailani—Iwalani—Ainaola Traffic Signal Improvement Project in Hilo on the island of Hawaii were studied to evaluate potential noise impacts associated with the four Build Alternatives. Noise measurements were obtained, traffic noise predictions developed, and noise abatement alternatives evaluated. Existing traffic noise levels in the project area do not exceed the U.S. Federal Highway Administration (FHWA) and Hawaii State Department of Transportation, Highways Division (HDOT) noise abatement criteria. Future ICY 2018) traffic noise levels with the proposed roadway improvement project are expected to exceed the "66 Leq" HDOT noise abatement criteria at four to six existing residences. Traffic noise mitigation measures in the form of noise barrier construction may be applied at these residences, but should be examined according to the criteria of reasonable and feasible. Because of the potential visual impacts of the noise barriers and the potential for graffiti, landscaping should be used on the roadway side of the barrier. The following general conclusions can be made in respect to the number of impacted structures and lands which can be expected by CY 2018 under the four Build Alternatives. These conclusions are valid as long as the future vehicle mixes and average speeds do not differ from the assumed values. A. The proposed HDOT's ">15 dB increase" criteria for substantial change in traffic noise levels will not be exceeded at any noise sensitive structure. Maximum increases in traffic noise levels in the project area should not exceed 4.3 dB as a result of growth in traffic volumes and construction of additional traffic lanes. B. Under Alternatives 1 A and 2A, future traffic noise levels at four and five homes, respectively, are expected to exceed the HDOT "66 Leq" criteria. Under Alternatives 1 B or 2B, future traffic noise levels at six homes are expected to exceed the HDOT "66 Leq" criteria. C. No parks or public use structures should be affected by the proposed project or require noise mitigation measures. D. No commercial structures should be affected by the proposed project or require noise mitigation measures. Page I Potential short term construction noise impacts are possible during the project construction period. However, minimizing these types of noise impacts is possible using standard curfew periods, properly muffled equipment, administrative controls, and construction barriers as required. Page 2i CHAPTER II. GENERAL STUDY METHODOLOGY Noise Measurements. Existing traffic and background ambient noise levels at twelve locations in the project area were measured in October 1997. The traffic noise measurements were used to calibrate the traffic noise model which was used to calculate the Base Year (CY 1997) and future (CY 2018) traffic noise levels under the No Build and Build Alternatives. The background ambient noise measurements were used to define existing noise levels at noise sensitive receptors which may be affected by the project. Also, the measurements were used in conjunction with forecasted traffic noise levels to determine if future traffic noise levels are predicted to "sub— stantially exceed" existing background ambient noise levels at these noise sensitive receptors, and therefore exceed FHWA and HDOT noise standards and criteria. The noise measurement locations ("A" thru "L") are shown in Figure 1. The results of the traffic noise measurements are summarized in Table 1. In the table, Leq represents the average (or equivalent), A—Weighted, Sound Level. A list and des— cription of the acoustical terminology used are contained in APPENDIX B. Traffic Noise Predictions. The Federal Highway Administration (FHWA) Traffic Noise Model (or TNM, see Reference 1) was used as the primary method of calculating Base Year and future traffic noise levels, with model parameters adjusted to reflect terrain, ground cover, and local shielding conditions. At the twelve traffic noise measurement locations along the project corridor (Locations "A" thru "L"), the measured noise levels were compared with model predictions to insure that measured and calculated noise levels for the existing conditions were consistent and in general agreement. As indicated in Table 1, spot counts of traffic volumes were also obtained during the measurement periods and were used to generate the Equivalent Sound Level (Leq) predictions shown in the table. The agreement between measured and predicted traffic noise levels was considered to be good at locations with moderately high traffic volumes and with visual line—of—sight to the roadway. At locations with very low traffic volumes ('B", "D", "E", "F", "J", "K", and "L"), local traffic noise levels did not exceed other background ambient noise levels, traffic noise model calibration was not possible. However, for those conditions where hourly traffic volumes were greater than 100 vehicles per hour, the traffic noise model used was considered to be sufficiently accurate to formulate the Base Year and future year traffic noise levels. Base Year traffic noise levels were then calculated along the project corridor using Base Year (1997) traffic volume data for the AM and PM peak hours from Reference 2. Traffic mix by vehicle types and average vehicle speeds for the various Page 5 LOCATIONS OF NOISE MEASUREMENT SITES FIGURE 1 q n�� Q) co U ~ c O O L N _ IN l0 ISD L � J � m V I` t` L N D1 L rtf O � w [No to L � J I x I U U) (u E F N O O N L O I- -� O = w v X U ~ z w ZI cL 2 o In io N rn LU Z I� L c� c0 n I 4 m W FQ- :F N W Q, _ cn U) CL m � L L N N Cl) L Cl) z > Q U U- > W cl Q ¢ U) o¢ o 000 0 0 00 o L O L o 000 0 0 c90o 0 0 o 000 L L ~ o~0 0~� CD o ^F In o� o forrl g0^ ES 1— I I I I I I I C: in u� in in c c vj , z U 'C ro O 'C U C ro U C ro U U 'C U U) w w ro0 a)w E oo^E EnEQ O ro n O� O Oro O OO OY Y Q a) O _ —i O N o O NL O O O T OLO C L C LC L C LO C IAC OC co N O O= 0 Q Q m m d d f Ire (% L i f �u �� LJ 1 b� wm U fD N rn (h N a)n n N fOD a J V � m O tD rn N h N O Nro O v v n to J IY IU w E 0 0 0 o co 0 0 cn -clf- W v Y �M 0 0 Cl O N v Q F- c W T Z i ui = O N nto O ED O I v carni rn to U v Q I¢ w a)_ W W d m O_ to N to Cl) m CM C\j V) Cl) Cl) Cl) FQ- Q U LL a ro LL cc Y-- (n O¢ O N O O M toto O II to v Q u) IT O O O o O O o O O O O O O o O in In v O v cc E„ o 0 1— I 1 I I 1 I I C - C C (!7 C CC ~C U) Z wa O w w U ro (D. U E!U w . a) . U w� U' (D U 'c w C w w w w C w ttl � wE mm e E c r E C E m -. .wEU o W o) oY 0) O 3 a 3 o Y Y rrn( O c�O c� OOO lL O N O N O N O (L N NO Jw O` w 0 LL w O� w O� w O� w O� w O� n — v uj LL� LL: 6 d = _ f Ire (% L i f �u �� LJ 1 f� r( i'� Lf.� O m N to to O W j (13 O m V v -T in in W J N [D j v y N V O) to rn Lo N N O <O to T co (U to v U') li LOLO J { X I U fN ♦- O O O O O :3 J p 1 W �U C[ to to0 LZ N D W Z J W cr O_ = O O O) ^� to N Z Z) I O n c� n N N O U Q I¢ W T W W a= m - a Cl) � � 0 < >LL� U LL 0 ¢�) ¢0 O o O o N0 � to 0 000 0 o co c)Otn o 008 800 o O 1- n co F- ^ o o H �- N U) F- to m F- OO> = 0 0 0 0 0 E t= I N I N I N I N N I N (n 1 v (n I N C` C` C C C C C 0 CO O N o o 7ro N 7 W Jmt y. ro ro r ro ¢� rn 0a°rn oa-~°') on° rn 0 3m U o ¢ °~�' o o¢ Q O N O N O -L N O N r O N r. F- O N O N tz J t{{-- L N O N O t} LL v 0 N O N O LL. N O d O C N C to N •C v O C y 'a — O G v et = In C N - v 10 v Cl) c� Cl) (0 f� r( i'� Lf.� sections of the existing and future roadway were derived from observations during the noise monitoring periods and from References 3 and 4. Determinations of the periods of highest hourly traffic volumes along the project corridor were made after reviewing the AM and PM peak hour traffic volumes from References 2 thru 4, and Figures 2 thru 4. The Equivalent (or Average) Hourly Sound Level [Leq(h)] noise descriptor was used to calculate the Base Year and CY 2018 traffic noise levels as required by Reference 5. Aerial photomaps, topographic maps, and project plans (where available) of the area were used to determine terrain, ground cover, and local shielding effects from building structures, which were entered into the noise prediction model. Future year (2018) traffic noise levels were then developed for the No Build and Build (roadway improvement) Alternatives using the future traffic assignments of Reference 2, the topographic and existing development features described previously, and the roadway alignment of the Build Alternative. Forecasted traffic mixes and speeds for Year 2018 were assumed to be similar for the No Build and Build Alternatives. The CY 2018 traffic assignments for the Build Alternative reflected the forecasted traffic volumes along the project corridor during the AM or PM peak hour, whichever is expected to have the highest hourly traffic volume. Future traffic conditions under the No Build Alternative may actually worsen, with average vehicle speeds declining as a result of increased congestion. Under the Build Alternative, average vehicle speeds are expected to remain the same as current values. Impact Assessments and Mitigation. Following the calculation of the future traffic noise levels for the No Build and Build Alternatives, comparisons of the future traffic noise levels and impacts among the alternatives were made. Comparisons of predicted future traffic noise levels with FHWA and HDOT noise abatement criteria (see Table 2) were made to determine specific locations where the noise abatement criteria are exceeded. In addition, the HDOT's criteria of "greater than 15 dB increase above existing background noise levels" was also used as a noise abatement threshold for this project (from Reference 6). Along the project corridor, the locations of the 66 thru 72 Leq(h) traffic noise contours, without the benefit of shielding from natural terrain or man—made sound barriers, were provided for siting future land uses along the project corridor, and for defining the adequate buffer space between the roadway sections and these land uses. The FHWA 67 Leq(h) standard shown in Table 2 and the HDOT "greater than 15 dB increase" criteria were applied to all noise sensitive buildings along the project corridor. In addition, the possibility of exceeding the 66 Leq(h) level was also examined for this study, since, by Reference 6, the HDOT Page `l HA G4 62 m 60 '-' 58 J W 56 W 54 N 0zZ 52 Z 50 > 48 O 46 W J 44 Q O 42 40 38 36 34 FIGURE 2 HOURLY VARIATIONS OF TRAFFIC NOISE AT 100 FT SETBACK DISTANCE FROM THE CENTERLINE OF KAWAILANI STREET WEST OF IWALANI STREET ( AUGUST 7, 1996 ) i 0300 0600 0900 1200 1500 TIME OF DAY (HRS) 0 100 FT from Roadway Centerline ( 59.9 Ldn ) 1800 2100 2400 7 MMIa v FIGURE 3 HOURLY VARIATIONS OF TRAFFIC NOISE AT 100 FT SETBACK DISTANCE FROM THE CENTERLINE OF KAWAILANI STREET EAST OF IWALANI STREET ( AUGUST 7, 1996 ) 66 64 62 60 58 56 54 52 50 48 4G 44 42 - 40 38 36 34 - 0300 0600 0900 1200 1500 1800 2100 2400 TIME OF DAY (HRS) 0 100 FT from Roadway Centerline ( 58.5 Ldn ) /0 n no n f � v FIGURE 4 HOURLY VARIATIONS OF TRAFFIC NOISE AT 100 FT SETBACK DISTANCE FROM THE CENTERLINE OF IWALANI STREET NORTH OF KAWAILANI STREET ( JUNE 261 1996 ) 66 - 64 - ---- --- 62 - 60 - m 3 58 - J w 56 - w 54 - e moi❑ '0 rL °z 52 - Z 50 - �j j 48 - I p 4G - w 44 - cc D 42 - — O 2 40 - 38 - 36 - 34 0300 0600 0900 1200 1500 1800 2100 2400 TIME OF DAY (HRS) ❑ 100 FT from Roadway Centerline ( 55.8 Ldn ) �� (1°nhf TABLE 2 FHWA NOISE ABATEMENT CRITERIA [1-lourly A—Weighted Sound Level --Decibels (dBA)] ACTIVITY CATEGORY LEQ li * DESCRIPTION OF ACTIVITY CATEGORY A 57 (Exterior) Lands on which serenity and quiet are of extra— ordinary significance and serve an important public need and where the preservation of those qualities is essential if the areas are to continue to serve their intended purpose. B 67 (Exterior) Picnic areas, recreation areas, playgrounds, activity sports areas, parks, residences, motels, hotels, churches, libraries, and hospitals. C 72 (Exterior) Developed lands, properties, or activities not included in Categories A or B above. D ------ Undeveloped lands. E 52 (interior) Residences, motels, hotels, public meeting rooms, schools, churches, libraries, hospitals, and auditoriums. * The Hawaii State Department of Transportation, Highways Division, utilizes Leq criteria levels which are 1 Leq unit less than the FHWA values shown. has replaced the FHWA 67 Leq(h) criteria with their 66 Leq(h) criteria. At the commercial establishments along the project corridor, the FHWA 72 Leq(h) and the HDOT 71 Leq(h) noise abatement criteria were applied to identify commercial establishments where noise abatement measures could also be applied. Where noise mitigation measures were indicated for this project, the effectiveness of sound attenuating barriers and other possible noise mitigation measures were evaluated. The ability to meet the HDOT criteria of 5 dBA noise reduction was also examined for various noise barrier heights. Where excessive wall heights above the 6 foot local code limit were required to meet noise abatement criteria, the HDOT "66 Leq" and "greater than 15 dBA increase" criteria took precedence over the HDOT "5 dBA reduction" requirement for noise abatement measures. Page 13 - CHAPTER III. EXISTING ACOUSTICAL ENVIRONMENT For the purposes of this study, 1997 was used as the Base Year for computing changes in traffic noise levels between the No Build and Build Alternatives. The Base Year noise environment along the project corridor was described by computing the Hourly Equivalent Sound Levels (Leq(h)j along the existing roadway during the AM and PM peak traffic hours for the 1997 time period. The hourly sound level, expressed in decibels, represents the average levels of traffic noise along the project roadways during the AM and PM peak hours of the study's Base Year. Table 3A presents the traffic volume, speed, and mix assumptions used to calculate the Base Year noise levels during the AM peak hour along the existing roadways in the project area. Shown in Table 3A are the calculated AM peak hour Leq(h)'s at reference distances of 50 and 100 FT from the centerline of the roadways. Table 3B presents similar calculations of existing noise levels along the same roadway sections during the PM peak hour. The calculated distances to the 57, 60, 66, 67, and 72 Leq noise contour lines under unobstructed, line—of—sight conditions to the roadway segment are shown in Tables 4A and 4B for the AM and PM peak hours, respectively. The actual distances to the contour lines will generally be less than indicated in Tables 4A or 46 when intervening structures or terrain obstructions exist between the roadway and a receptor. This reduction (or shrinkage) of the traffic noise contour distances from the roadway's centerline is the result of noise shielding (or attenuation) effects caused by the intervening structures or natural terrain features. By using the traffic noise data shown in Tables 3A thru 46, and aerial photos of the existing improvements on the west side of the project corridor, the relationship of the existing free—field traffic noise contours to existing noise sensitive dwellings in the project area were obtained. Similar evaluations were provided for those areas where commercial structures are located. A tabulation of public and private structures or park lands where the FHWA and/or the proposed HDOT noise abatement criteria may be exceeded along the project corridor during the Base Year is provided in Table 5. From Table 5, it was concluded that both the FHWA and the proposed HDOT noise abatement criteria were not exceeded in the project area during the AM or PM peak traffic hours during the Base Year. At areas removed from the higher volume roadways, Base Year noise levels are much lower than along the roadways' Rights—of—Way due to distance factors and local shielding effects from buildings. Base Year noise levels in areas removed from Page 14 ; - � i i i J M� i7 L i�!i n CT) W J m 1s 0 z G� f I Ll l� l J O to I` I- 7 r- Kr V' V N (O Ri cri Cp O Oi Il� tD (A t- cy) CO (O (6 O IOU) N m N In 7 (VO (D (O (O UD (O In C 0 K N 7 1D (O IA U J x to W * Y W J it ¢ ^ F- W =_ a O¢ >� z ¢ to v Q W 0 ([ co N QU r J� ui O> Cl) Cn WO O U), N(1) CM Lo .� Q Z) * * F- vM OD U) cO 7°rn co V' N .-- (O In a 0 * a J Oz= > — Y J U a Q= to to N V) N ao m N o) O C`) to U} W f- n OD 00 to Cl) C) CO (7 OA r ¢ O> CO CO N. ((0 LL f - Q ¢� O v W= N N to O N In to to IA N v a v Q W p„ O Cl) (7 Cl) C) 0 N O Cl) C.) C) Cl) 0 a 5_ rn � z O r U C7 z H U) X < CD a 0 w W w 0 N N al t L E E E E E o rnrnrnCnrn 0.- zU) Cl) (n (D U) - - r 0 0 w v v v w 0 v a d z Cn Q b (n (n CO d tninininin �' °? aa)i a) O C C C C C N a) N (D (a O w (p 7 7 7 (a •- .- b m Y Y Y C 3 3 3 3 3 t m t t t rt YY WoYYYY c ca 3 3 aa-cL 1s 0 z G� f I Ll l� l a O A N F -Z N O co, C O O V N N Y m of N n Y V r a Q) M M to r� O N n m W O a] d N J .- (D N (D W 7 (D c7 W N 1n M ? d' (O to 66 d' O <o W 6 V O LO J« co W x M Y w % J * H W = _ U) a O ¢ w Y G cr N H ¢ U J W O w 3 Wc O ^ cc > m O CO WO to O IT to Y Y N f� t7 O a0 v v c7 OI T C Q � « k F to (D N O1 N n N « Ja0 O Z Cl) > X J Lntnarnwow 00 rnrnv UUW dl nT(D—Tcl Lf)i nuWio m u ¢<a �> LL ¢ cc ¢ 0- 0 v w= W N m N in O N LO N N to N 7 V I. c Q 4. N N Cl) N N N m (7 m 0 Cl) m y IL Ol U) O) r- Z ur O d U Q s .� (n 0 c Z m 'ro F7 - U) Y w o c c c c c a) c E E E E E V- 0) a 0) a 0) wai 0) 0) a O Z O (n Z (n (n (n to (n - -c O m a v c v v v w Z (n ro U O U) U) U) U)U)b �_ a -C ro -C ro -C ro > ar C: s a) LL c ro aro 6 c 3 3 3 3 3 c w L L t tl° o (Uro ro ro ro t o 0 0 5 3 3 YXYYYYWn.0.aQ Z TABLE 3C IDENTIFICATION OF KAWAILANI STREET ROADWAY SEGMENTS SEGMENTS BOUNDING INTERSECTIONS (a) Kapualani St. to Private Drive (b) Private Drive to Kuhilani St. (o) Kuhilani St. to Pohakulani St. (d) Pohakulani St. to Iwalani St. (e) Iwalani St. to Kanoelani St. �7 ® G� � � � b r r• M � J O O Q Q Q Q Q Q Q W n z z z z z z z z J W y� Z JI LU U z z Z Z Z Z W p U O � Wco m N N N n N V N Z z Z Z Z z LL Y U IDJ w J U N n 0 a N n O o D m Q Q Q a a Q rD Z 0 Q Z Z z H W � Ln U) mlQ M n z z N z m ¢Y W o vm IL W -•7 uai u�i o U) .n m n uO1i rl% v It oDi n a) a v a aDi v u� N W J p' u�i co (� Ol J T Er J f'- a <D m l0 W N an0 (-�} ppn� N <D .- N C.Nj (nt'] p(� V N fD } O > (0 F- Z x in ur ur O q v7 z w "'� ~ Z U ao N o`, N o N 0 N 0 N o fV v� (V ui uN i N i fV i o N0 o,N N U z w¢ rn rn rn rn rn rn m rn rn rn M rn rn >o Z U p w x a x a x a z a x a x 0- x a x a x a x a x a x a x a LLl a N N O N to V/ to U0 Uf a y It ?• F- Q Z Q m U O w w d W U) W M) in in in in UC) d m 9 3 75 N N Q (7 0 LU mc b b m b m m m m cc U)3 3 3 3 3 L d a a. d° °m Y Y Y Y Y x W Z fn c a Z N b r r• . o J Q Q to Q Q Q Q Q 6 Q W^ Z .- Z .- z Z z Z Z z Z Z J a LU W n Z z Z Z Z N Z U N t11 CJ : o U ° Z tl_ J < LL to z z z z z � o YLU J O D N U Q U Z 0 N p Z Z Z N Z m Q (D 0 vi a O mI J to v O (0 tD toa (0N N Z Z v Z a t0 •- 2 tt'n YQQQ o m ^ m O N O N Ul f0 7 .- N .- O r w d @j'a �. N to n N O t0 tO to to V N N O 7 (V to V M to tN N Q C _1 a. CO m F rn I U J W I n { ? N 00 v ^ { to O ^ O(L ttOO y omi Z x O o O O O O O to N n n N O O 1n Z N N N N N (V N N N (V f7 N O 10O O O O O N N N N O 8 O tll -_ Q rn rn m rn W a) rn m a) a) o) rn 0) 0)U > O o Z pWI S 2 = S 2 S = S 2 2 S S S a EL a a 0. 6. a a a a a a a. w in flll 0 m M m n Cl)N N Cl) Cl) N %" Q m U O W d W N W Q % , LLlro in in N d U 9 'C a CC m d Un cn to O Y .2 O td N N N f° C C Y t0 t=Q t9 C C CC U 3 3 3 as 3 3 3 3 r w a° 0.° Y Y Y Y Y Y W Z Z (n I 1r �LI r its ��i� �� I TABLE 5 LIST OF NOISE IMPACTED STRUCTURES AND LAND AREAS DURING BASE YEAR (CY 1997) *** NUMDER OF IMPACTED UNITS ( BASE YEAR LEO) *** ROADWAY PRIVATE PUBLIC USE PARK SEGMENT STRUCTURES STRUCTURES LANDS Kawailani St. (A) 0 0 None Kawailani St, (D) 0 0 None Kawailani St. (C) 0 0 None Kawailani St. (D) 0 0 None Kawailani St. (E) 0 0 None Kuhilani Street 0 0 None Ehehene Place 0 0 None N. Pohakulani St. 0 0 None M. Pohakulani St. 0 0 None S. Pohakulani St. 0 0 None Ainaola Drive 0 0 None N. Iwalani St. 0 0 None S. Iwalani St. 0 0 None TOTALS: -------- 0 -------- 0 ----- 0 the higher volume roadways are typically less than 50 Leq(h), and possibly as low as 40 Leq(h). This was evident from measurements of existing background ambient noise levels at Locations B", "E", "F', "J", "K", and "L", as shown in Table 1. l Page I �Ld!;1 lr CHAPTER IV. DESCRIPTION OF FUTURE TRAFFIC NOISE LEVELS The future traffic noise levels in the immediate vicinity of the project during CY 2018 were evaluated for the No Build and Build study alternatives. The same methodology that was used to calculate the Base Year noise levels was also used to calculate the Year 2018 noise levels. It should be noted that forecasted traffic volumes for both the No Build and Build Alternatives were not available at all of the street segments which were evaluated for the Base Year. Under both the No Build and Build Alternatives, average vehicle speeds and traffic mix were assumed to be identical to the Base Year values. Tables 6A and 6B summarize the traffic conditions, noise levels, and setback distances for the No Build Alternative during the AM and PM peak hours in CY 2018. Traf— fic noise levels in the immediate vicinity of the project are predicted to increase by 0.6 to 2.7 dB between CY 1997 and CY 2016 as a result of projected traffic volume increases. However, Table 7 indicates that both the FHWA and the proposed HDOT noise abatement criteria should not be exceeded in the project area during the AM or PM peak traffic hours during CY 2018 under the No Build Alternative. The future (CY 2018) traffic volume, speed, and mix assumptions used for the Build Alternatives during the AM and PM peak traffic hours, respectively, are shown in Tables 8A and 8B. Also shown in the tables are the future traffic noise levels at reference distances of 50 and 100 FT from the roadways' baselines. Table 8A and 8B apply to all four Build Alternatives (1A, 2A, 1B, and 2B). Only the roadways' configurations and striping varied among the four Build Alternatives. Figure 5 presents the fifteen noise sensitive receptor locations where future traffic noise levels were calculated for the four Build Alternatives using the FHWA Traffic Noise Model. The predicted CY 2018 traffic noise levels at these fifteen receptor locations are shown in Tables 9A and 96. At seven of the fifteen locations, future traffic noise levels are expected to exceed the HDOT "66 Leq" noise abatement criteria, with predicted increases of 2.2 to 4.3 Leq between CY 1997 and CY 2016. These seven receptor locations represent the locations of six existing homes where potential traffic noise impacts are possible from the roadway improvements. The following general conclusions can be made in respect to the number of impacted structures and lands which can be expected by CY 2018 under the four Build Alternatives. These conclusions are valid as long as the future vehicle mixes and average speeds do not differ from the assumed values. Page alt � �rr II; II «Q « Jcq ¢ Q Q T Q Q ZN Z Z Z Z Z n J W Z -� N m Q d ¢ N N Q W n Z Z Z Z ULU U 0� N Z ^ Z Z Z Z Q tic O W a rn o Z Z Of .°�' UO Y ° U ¢ m ^^ op O N W p J N ^ Z N Z V' W . n « All Q 2 tul U O to m n O N O O N ¢ ¢ .- W = CL m ¢ o W o J m •' m O th ,n Q Ulm to tic a v u�i LO I— N Q' u crJ Q W r ¢ A cq t t00 p 4 N O N pNO N (L F j O to r N r N m n N z r O Xz o O U) O O O O O O O O U UJ 0 0 o o o LQ LQ kq vii, S �' n n n n n t` vi n n Wa) o) 0) a) 0) 0) m 0) 0) M p S = m 2 S S 2 2 S z Z W� m .2 2 ;EI `2 2` 2 2 ct � � cli M M co)0 cri ccn c¢7 } 'c c 'c tociO ]V) m m ro m p ro L L b ¢ 3 3 3 ti ti � 3 3 Y Y Y Z fn c Q Z 0 m w w J m Q r U) w U z a U- X U Q m w W U) a T Y w W CL a c9 N Q w U Z O f= O Z O U 0 J_ D m O z Q � Q Q z z z z Z N Z Z Z Z Z _ r J Q w m Z-' N °4 civ Q Q LU r Z z z U <p O0 o) m J N ? O Z Z N Z a tz UJ r N OI Z c-1 Z O 10 Z U O Z � F N <p In O Q N to c0 O J (7)Z U (0 rn r In Lu a Z rn rn o o rn rn o o a U 0 U m rN C7 O t^p 0 t tO IA ? N to w uI .} v 01 J J Q =I =i rn ci of n m n O > v F- ul ul Q o cv Q o O O O I I IA N O O N 2< rr r r r r In r r w a a) m (7) rn a) m (7) 0)m i o� w a a a a (L a a a a CL U)M CI N O M O M N M U in Q Z c c O in U) w Q C C C TUAMMMM-T19a ¢ � 3 > 3 a° a° a° °m 3 3 c Y Y Y Z h a Z N TABLE 7 LIST OF NOISE IMPACTED STRUCTURES AND LAND AREAS IN CY 2018 UNDER NO—BUILD ALTERNATIVE ** NUMBER OF IMPACTED UNITS ( YEAR 2018 Leq) ** ROADWAY PRIVATE PUBLIC USE PARK SEGMENT STRUCTURES STRUCTURES LANDS Kawailani St. (A) N/A 0 None Kawailani St. (D) N/A 0 None Kawailani St. (C) 0 0 None Kawailani St. (D) 0 0 None Kawailani St. (E) 0 0 None Kuhilani Street N/A 0 None Ehehene Place N/A 0 None N. Pohakulani St. 0 0 None M. Pohakulani St. 0 0 None S. Pohakulani St. 0 0 None Ainaola Drive 0 0 None N. Iwalani St. 0 0 None S. Iwalani St. 0 0 None TOTAL -------- 0 -------- 0 ----- 0 r� ( Q co W J C13 a a) J orn n v Dom Oi O O (A Cl) (Ot- (o (O (O If to N It O J (n at O 01 — to to (7 to to N 46 o O (O CO (D (o tD cp tto � * N W >•- W « ¢ r _ W 0. _ > O w Z 0. v Q W N V to to .- v rL ¢ N Cl) m N — H Q w O Q> O W k O O w to N m (N N ap * a J ci C) Z > {n Y Q J Q 2 (n O O to (n N W J pN (p N N m (v N m Q a o> ~ �a LL. Q CL Q p F -p W=Ito W0. O N co c7m(7)c1)coco io V It M C 00 CL Ev c7 U) o a N O w } J U Q in w [C — 'b � LL UO W— C: C C C C m w v L O E E O N Z i m m w J CD t-- �q U r> w J m v N c w E rn w N v m S E ro 3 to Y O C O m U w. c v 0 LL r—i f (I ��F1, m cD O N -t -r r- O Di c0 O tri cp C01J O to O N v (D u) v r7Gl V -7 O N O) 01 cp J N to 7 c7 7 (3) O W W W to tD O M M N J * U cDCD��0a w r cv > * ¢ w ~ J 7 - CL a w > U IY O w W Z N N 0 )D O O c7 O N') .— QQ j� J :2z~ O w > cq O N co D) O to lD '3 w 0 ^ CC M e O ! N m to W c0 7 N (D 0) 10 V O « a IL J z = J >O —Y Ha ' 0 o CIJ irr, 0 to 0 It Q O >I CO W N NQ � v ¢ aw LL�: QOa o� w2 tooN)nvvv ¢ 0 w a co c)Co ) c7 m CI) 0- C) Z oz NO J U w cr ~ U W_ LL C C C al al a) L E E E r 0 Z Z a) a) a) L o r 'O O a w w v v z cn � vU) a) w d U U) U) ro a) OJ m C) 6 3 3 X 3 L ro c m Y Y Y m 3 3 a- Q ZI �q U r> w J m v N c w E rn w N v m S E ro 3 to Y O C O m U w. c v 0 LL r—i f (I ��F1, in 0 All TABLE 9A SUMMARY OF EXISTING AND PREDICTED TRAFFIC NOISE LEVELS AT NOISE SENSITIVE RECEPTOR LOCATIONS #1 THROUGH #15 ( 4.92 FT RECEPTOR, AM PEAK HOUR) Notes: 1. Right—of—Way (RNV) wall locations as shown in FIGURES 9D through 9F. 2. *Doi iotes exceedance of Slate DOT "> 15 dB Increase" Criteria. 3. •" Denotes exceedance of Stale DOT GG Leq Criteria for Residences. 30 EXISTING -------- FUTURE (CY 2018) Leq--------- RECEPTOR DISTANCE (CY 1997) ALT, to / ALT. 2A / ALT. 18 / ALT. 28 / LOCATION FROM CIL Leo (CHANGE) (CHANGE) (CHANGEI (CHANGE) 1 (Dwelling) 60 FT 63.8 65.5/(1.7) 65.5/(1.7) 66.2/(2.4) " 66.2/(2.4) •" 2 (Dwelling) 57 FT 64.1 6G.1/(2.0) `• 66.1/(2.0) •• 66.6/(2.5) "• 66.6/(2.5) •' 3 (Dwelling) 66 FT 61.5 64.3/(2.8) 64.3/(2.8) 64.2/(2.7) 64.1/(2.6) 4(Dwelling) 60 FT 63.6 64.9/(1.1) 64.9/(1.1) 64.8/(1.0) 64.8/(1.0) 5 (Dwelling) 50 FT 64.2 67.0/(2.8) "• 67.0/(2.8) •• 67.8/(3.6) "' 67.8/(3.6) •' 6 (Dwelling) 60 FT 63.0 66.7/(3.7) " 66.7/(3.7) `• 67.2/(4.2) "' 67.2/(4.2) 7 (Dwelling) 50 FT 64.2 GG.5/(2.3) •' 66.5/(2.3) '" 67.2/(3.0) "" 67.1/(2.9) •' 8 (Dwelling) 59 FT 61.4 64.9/(3.5) 65.0/(3.6) 64.9/(3.5) 64.9/(3.5) 9 (Dwelling) 60 FT 61.3 63.3/(2.0) 63.2/(1.9) 63.2/(1.9) 63.2/(1.9) 10 (Dwelling) 100 FT 58.4 61.6/(3.2) 61.5/(3.1) 61.9/(3.5) 62.0/(3.6) 11 (Dwelling) 50 FT 63.0 GG.2/(3.2) •" 67.1/(4.1) •• 67.2/(4.2) " 67.1/(4.1) •• 12 (Dwelling) 45 FT 63.6 65.1/(1.5) 66.8/(3.2) •• 66.8/(3.2) *" 67.9/(4.3) •• 13 (Dwelling) 65 FT 61.2 62.1/(0.9) 61.7/(0.5) 61.9/(0.7) 62.0/(0.8) 14 (Dwelling) 55 FT 62.3 63.0/(0.7) 63.6/(1.3) 63.6/(1.3) 63.9/(1.6) 15 (Dwelling) 80 FT 59.9 60.8/(0.9) 60.7/(0.8) 61.0/(1.1) 61.0/(1.1) Notes: 1. Right—of—Way (RNV) wall locations as shown in FIGURES 9D through 9F. 2. *Doi iotes exceedance of Slate DOT "> 15 dB Increase" Criteria. 3. •" Denotes exceedance of Stale DOT GG Leq Criteria for Residences. 30 TABLE 9B SUMMARY OF EXISTING AND PREDICTED TRAFFIC NOISE LEVELS AT NOISE SENSITIVE RECEPTOR LOCATIONS #1 THROUGH #15 ( 4.92 FT RECEPTOR, PM PEAK HOUR) Notes: 1. Riehl—of—Way (n/W) wall localions as shown in FIGURES 9F through 9H. 2. • Denotes exceedance of Slate DOT *> 15 dB Increase' Criteria. 3. "" Denotes exceedance of Slate DOT GG Leq Criteria for Residences. EXISTING -------- FUTURE (CY 2018) Leq--------- RECEPTOR DISTANCE ICY 1997) ALT. 1A / ALT. 2A / ALT. 1B / ALT. 28 / LOCATION FROM CIL Leu (CHANGE) (CHANGE) (CHANGE) (CHANGE) 1 (Dwelling) GO FT 63.5 65.1/(1.6) 65.2/(1.7) 2 (Dwelling) 57 FT 63.9 65.4/(1.5) 65.41(1.5) 3 (Dwelling) 8G FT 61.2 63.5/(2.3) 63.5/(2.3) 4 (Dwelling) GO FT G3.5 64.9/(1.4) 64.9/(1.4) 5 (Dwelling) 50 FT 63.0 66.1/(3.1)•' 66.1/(3.1)" 6 (Dwelling) GO FT 61.8 65.31(3.5) 65.31(3.5) 7 (Dwelling) 50 FT G3.O 65.3/(2.3) 65.3/(2.3) 8 (Dwelling) 59 FT 60.4 65.0/(4.6) 65.1/(4.7) 9 (Dwelling) 60 FT 60.3 62.5/(2.2) 62.5/(2.2) 10 (Dwelling) 100 FT 59.1 62.1/(3.0) 62.4/(3.3) 11 (Dwelling) 50 FT G3.G 66.4/(2.8)" 66.4/(2.8)'- 6.4/(2.8)"12 12(Dwelling) 45 FT 64.3 66.5/(2.2)" 67.4/(3.1) 13 (Dwelling) 65 FT 61.9 62.9/(1.0) 62.9/(1.0) 14 (Dwelling) 55 FT 63.0 63.8/(0.8) 64.0/(1.0) 15 (Dwelling) 80 FT 60.G 61.9/(1.3) 61.9/(1.3) Notes: 1. Riehl—of—Way (n/W) wall localions as shown in FIGURES 9F through 9H. 2. • Denotes exceedance of Slate DOT *> 15 dB Increase' Criteria. 3. "" Denotes exceedance of Slate DOT GG Leq Criteria for Residences. A. The proposed HDOT's ">15 dB increase" criteria for substantial change in traffic noise levels will not be exceeded at any noise sensitive structure. Maximum increases in traffic noise levels in the project area should not exceed 4.3 dB as a result of growth in traffic volumes and construction of additional traffic lanes. B. Under Alternatives 1 A and 2A, future traffic noise levels at four and five homes, respectively, are expected to exceed the HDOT "66 Leq" criteria. Under Alternatives 1 B or 213, future traffic noise levels at six homes are expected to exceed the HDOT "66 Leq" criteria. C. No parks or public use structures should be affected by the proposed project or require noise mitigation measures. D. No commercial structures should be affected by the proposed project or require noise mitigation measures. n r -i Page 3 Z CHAPTER V. POSSIBLE NOISE MITIGATION MEASURES Possible noise mitigation measures considered included the following: A. Restricting the Growth In the Number of Noisy Buses Heavy Trucks Motor— cycles, and Automobiles with Defective Mufflers. The percentage contribution to the total traffic noise by heavy trucks, buses, and noisy vehicles is currently in the order of 55 percent, and elimination of these noise sources would reduce total traffic noise levels by approximately 3 dB. Restricting the growth rate of these vehicles (to growth rates below passenger automobile growth rates) could produce noise reductions in the order of 1 or 2 dB, which are not considered significant for the level of regulatory efforts required. B. Alteration of the Horizontal Or Vertical Alignment of the Roadway. Major alterations of the horizontal or vertical alignment of the existing roadways were not considered appropriate due to the scope of this roadway improvement project and due to the Right—of—Way constraints on all sides of the affected roadways. The possible roadway alignments are controlled by the required intersection improvements. At the Kawailani and Iwalani Street intersection where four homes qualify for noise mitigation measures, the alignment of Kawailani Street is essentially constrained by existing buildings north and south of Kawailani Street. Lateral displacement of Kawailani Street toward the north would require demolition of the south side of the existing Hawaiian Telephone Building, as well as a bend toward the north of the existing roadway alignment at the intersection. A similar situation exists along Ainaola Drive where two homes at Receptor Locations 11 and 12 are situated. A bend toward the northwest of Ainaola Drive would be required just southwest of the intersection with Kawailani Street. Vertical realignment of the existing roadways upward would result in adverse visual impacts, and vertical realignment of the roadway via a cut would not be possible without obtaining additional Right—of—Way. For these reasons, realignment of the existing roadways away from the affected homes was not considered to be a reasonable noise mitigation measure. C. Acquisition of Property Rights for Construction of Noise Barriers and/or Construction of Noise Barriers Along the Right—of—Way. For single story, noise sensitive buildings, construction of a sound attenuating wall is normally the preferred noise mitigation measure. The 6 to 7 dB of noise attenuation achievable with a 6 FT high wall is normally sufficient for single story structures. Because five of the six affected homes are one—story structures, construction of a sound attenuating barrier could possibly provide sufficient noise reduction benefits to the affected homes. It should be noted, however, that the sound barrier will block the views to the roadway which some Page 3-3 �� r)� l_' Ji' �A lr If of the residents may enjoy. For this reason, concurrence from the affected homeowners should be obtained prior to construction of a sound barrier as a noise mitigation measure. D. Acquisition of Real Property Interests To Serve As A Noise Buffer Zone. Where tall (or multistory) structures are expected to be impacted by future traffic noise, the use of sound attenuating barriers (see para. C above) will not be practical due to the excessive heights required to shield the upper levels from traffic noise. In these situations, the only other noise mitigation possibilities are sound insulation of the affected upper level units or acquisition of the property interests. Noise buffer zones extending approximately 65 to 70 feet from the roadways' baselines and at substantial cost would be required to meet the HDOT 66 Leq criteria. In general, the acquisition of property for the creation of noise buffer zones or noise mitigation has seldom been applied in Hawaii. E. Noise Insulation of Public Use or Nonprofit Institutional Structures. Public use or nonprofit institutional structures should not be impacted by this project For this reason, noise insulation of public use or nonprofit institutional structures should not be required. Page ,'� r �i CHAPTER VI. FUTURE TRAFFIC NOISE IMPACTS AND RECOMMENDED NOISE MITIGATION MEASURES Future traffic noise levels are predicted to exceed the HDOT 66 Leq(h) and FHWA 67 Leq(h) noise abatement criteria by CY 2018 with the project at existing noise sensitive dwellings along Kawailani Street and Ainaola Drive. Table 10 presents the predicted performances of sound attenuation walls located along the Right—of—Way and in front of the affected homes. Figures 6 thru 11 depict the locations of the affected homes and the sound attenuation walls which were evaluated. Mitigation of future traffic noise at the second floor of the existing home at Location 2 will not be feasible using a sound wall along the roadway Right—of—Way, since a wall height in excess of 8 feet above roadway grade is required to shield the elevated living unit from traffic noise. Use of alternate noise mitigation measures, such as window air conditioning units for the second floor living areas is recommended. The use of a 5.5 to 6.0 foot high sound attenuating walls is recommended where shown in Figures 6 thru 11 for the various Build Alternatives. The predicted future noise levels for the recommended wall heights shown in Figures 6 thru 11 are shown in Table 10 under the "RECOM. WALL" column. Although the HDOT "5 dBA noise reduction" criteria will not be met at Locations #1, #7, and #12 by the recommended wall heights, the construction of walls exceeding 6 feet in height is not considered to be reasonable since the HDOT "66 Leq" noise abatement criteria will be met with wall heights of 6 feet or less in all ground level living areas. A variance from local building codes will be required to construct the 6.5 to 7.0 foot high walls which are required to achieve 5 dBA of noise reduction vs. the 4.3 to 4.9 dBA of noise reduction provided by the recommended wall heights. The sound attenuating walls must be continuous without see—through openings, and may be constructed from solid materials which have a minimum surface weight of 5 pounds per square foot. Use of landscaping on the roadway side of the wall is also recommended to soften the visual impacts of the walls and to minimize the potential for graffiti. It is anticipated that potential noise impacts at any new noise sensitive or commercial establishments located in the project area may be mitigated through the inclusion of sound walls or other noise mitigation measures within the individual lot development plans. In addition, any new commercial establishments or housing units which may be planned alongside the roadway represent areas of potential adverse noise impacts if adequate noise mitigation measures are not incorporated into the planning of these future projects. It is anticipated that the project's roadway improvements will be completed prior to any redevelopment of the presently open Page 3 5 i O_ W J C3 Q I' - W _ _ Q Q W_ :3¢0 CC= Q (n ¢Y¢ N W > a O a.. Q CC �0 z� W Q a� W O N ICL Z U W U cc LL� LL CC C\j Q) 04 W U_ Q W a I Q_j I I I L l 0� J O J Oru N a U Z W = ¢ U 10 F - LL LL J a t7 13F- 1 LL 4 U I N I ¢ Z 00 w Q W U ¢ GJ A N O N <T O v a t7 a e7 ci t0 u t0 t0 r0 to L L rl L L L N O O O O 0 N N O N P Y a N N ♦ r • > i m Z v > t7 1 N 1 1 N 1 N 1 1 a O\ S 1 O 0i N O m A N N\ to O N O t0 .0 N to N tO m t0 t0 � b O N t0 t0 �0 �0 to to 0 ♦ U V tv � m, o m m l7 I t7 1 .� I N I l7 1 I ¢ ¢ ¢ ¢ ¢ ¢ i� N N ro O Ot 0 0 0 t0 t0 e e e � OI O N OSI 00 m �0 e e tN0 tN0 ci I. O N O N .0 t0 a to �o t0 l7 l7 i i t7 i • PI O 0 O o i0 0' m' rn o M i l l i to o e o i0 N N N O O b tD O O ¢ Z 00 w Q W U ¢ GJ A N O N <T O v a t7 a e7 ci t0 u t0 t0 r0 to L L rl L L L N O O O O 0 N N O N P Y a N N ♦ r • > i m Z v > > i N 1 6 1 a O\ S 1 O 0i N O m m tri a to a r; to 3 U t0 .0 to to to t0 ¢ Z 00 w Q W U ¢ GJ A N O N <T O v a t7 a e7 ci t0 u t0 t0 r0 to L L rl L L L N O O O O 0 N N O N P Y a N N • ♦ r • > i i > > i N 1 6 1 0i 1 1 0i - 1 a m w a 0 m ¢ ¢ ¢ ¢ ¢ ¢ • ♦ r • a N 1 6 1 N 1 1 1 N 1 - 1 t7 m N t�0 Q CI 0 O 0 0 N O N t0 t0 �0 �0 to to 0 ♦ U V V U V V U m m m m m m m ¢ ¢ ¢ ¢ ¢ ¢ ¢ N 7 O N N O O l7 N OI O N OSI 00 m �0 e e tN0 tN0 t!1 CJ Q F� O OI N N l7 l7 i i t7 i PI O 0 O O .. m N 0 O m tV 1 tV 1 N 1 1 1 N 1 0 1 n �? to to n m U` O O O b b b b a to �o ry o aasmass N 10 m (. cV Q . N O N OI 0 b tip b b b b b O A O O O O N t0 to N t0 N O Q < a 56 jI ;;. ('.,1 � = Ol N1 y 2 m c v G U G O m 7 c m a - N c_3a 0 C Q `• m m C n V £ d 0 o o e m m a0 U) U ¢ — ¢ ¢ N N m m cmc c C7�mm 0'A iz u c E'A u co *(r gto m O O J d> N N O L m e u m~tE¢m c O a o o m 9 Ig c E urns o 09 O A t O O 'D Z 0 O m m V O U U m N S m g O I m cc 0 m '� m m y ®c o 3 H N N O I m m m 0 ._ m O C L C t m m m C - r � 0 0$ 3 2 • i y n � N 7 O n t6 a a 0 0 0 > > 0 > U V V U V V U m m m m m m m ¢ ¢ ¢ ¢ ¢ ¢ ¢ 56 jI ;;. ('.,1 � = Ol N1 y 2 m c v G U G O m 7 c m a - N c_3a 0 C Q `• m m C n V £ d 0 o o e m m a0 U) U ¢ — ¢ ¢ N N m m cmc c C7�mm 0'A iz u c E'A u co *(r gto m O O J d> N N O L m e u m~tE¢m c O a o o m 9 Ig c E urns o 09 O A t O O 'D Z 0 O m m V O U U m N S m g O I m cc 0 m '� m m y ®c o 3 H N N O I m m m 0 ._ m O C L C t m m m C - r � 0 0$ 3 2 • i y n � N 7 O n t6 W co O Z a W 0 Z W O U W cr LL O W 7 H Q Z CC W Q cc O LL F -- W W ccN CZ ) ZZ O¢ Q r �m 1501 rfalI` I Fr ; ; N x U ..... .1 ;1 ' I 1 UJ ' 1 V); 1/7 �t- • I i Ln�' LO ' 1t d' V Lrr •• I.•, • , 10 44 (J '133dlS INVIVMI..,t :f ,.r ',�E-4:�i •�: °°' • ...Sr -� -tom i , �m I W U) W LU > cc ryQ ~ W z W x (1) W Z Q ocr- W O0 Z� w �w O H cc Z g OQ tom Z O 0 Z U ZO Q O .� m 1501 rfalI` Fr ; ; N x U ..... .1 ;1 ' I 1 UJ ' 1 V); 1/7 �t- I W U) W LU > cc ryQ ~ W z W x (1) W Z Q ocr- W O0 Z� w �w O H cc Z g OQ tom Z O 0 Z U ZO Q O .� m I t h t W 00 C7 LL wQ Q T X L11 W N z cr- ZJ W cc O� ZLU U- c� W i OR U 0 LU x Q LLO OQ z oa CD az o -j I I 11 C13 I a W` LLJ in Z 0x Z LU LLJ Z o LLI LL LU 0? 0 cc LLI C) cc LL 0 0 U) z z 0 0 Z ID 0 0 C'4 LLJ C13 I a W` LLJ in Z 0x Z LU LLJ Z o LLI LL LU 0? 0 cc LLI C) cc LL 0 0 U) z z 0 0 Z ID 0 0 areas or commercial lots adjacent to a roadway, and that noise abatement measures such as adequate setbacks, sound attenuating walls or berms, or closure and air conditioning will be incorporated into these new developments along a roadway as required. In any event, new structures whose building permits were obtained after the date of this noise study will not qualify for noise abatement measures under existing HDOT procedures. Page CHAPTER VII. CONSTRUCTION NOISE IMPACTS Short—term noise impacts associated with construction activities along the existing roadway may occur. These impacts can occur as a result of the short distances (less than 100 FT) between existing dwelling units and commercial establishments to the anticipated construction corridor. The total duration of the construction period for the proposed project is not known, but noise exposure from construction activities at any one receptor location is not expected to be continuous during the total construction period. Noise levels of diesel powered construction equipment typically range from 80 to 90 dB at 50 FT distance. Typical levels of noise from construction activity (exclu— ding pile driving activity) are shown in Figure 12. Adverse impacts from construction noise are not expected to be in the 'public health and welfare" category due to the temporary nature of the work and due to the administrative controls available for its regulation. Instead, these impacts will probably be limited to the temporary degra— dation of the quality of the acoustic environment in the immediate vicinity of the project site. Construction noise levels at existing structures can intermittently exceed 90 dB when work is being performed at close distances in front of these structures. Along the north portion of the roadway improvement project, distances between the con— struction sites and receptors are expected to be between 10 and 100 FT, and construction noise levels may intermittently exceed 90 dB. The State Department of Health currently regulates noise from construction activities under a permit system (Reference 7). Under current permit procedures (see Table 11), noisy construction activities are restricted to hours between 7:00 AM and 6:00 PM, from Monday through Friday, and exclude certain holidays. Noisy construction activities are normally restricted to the hours of 9:00 AM to 6:00 PM on Saturdays, with construction not permitted on Sundays. These restrictions minimize construction noise impacts on noise sensitive receptors along the roadway project corridor, and have generally been successfully applied. In this way, construction noise impacts on noise sensitive receptors can be minimized. In addition, the use of quieted portable engine generators and diesel equipment should be specified for use within 500 FT of noise sensitive properties. Heavy truck and equipment staging areas should also be located at areas which are at least 500 FT from noise sensitive properties whenever possible. Truck routes which avoid resi— dential communities should be identified wherever possible. The use of 8 to 12 FT Page%� Li �'�: �iL, CONSTRUCTION NOISE LEVELS VS. DISTANCE FIGURE 12 0 0 T ^O V r 0 0 0 -o Z co 0 -o N 0 = U Q E 0 try Z 0 CL o' 0 00 w U N a� Oj w ca C� z o o Zcr > o C) w rn W -� U CL 0 Oz U H Q rn Lbb 6 6 �b bT ado abo T 9p ui Iana-1 punoS pa146iaM-V CONSTRUCTION NOISE LEVELS VS. DISTANCE FIGURE 12 -o T ^O V r 0 0 0 -o co 0 -o N 0 0 try 0 0 N O CONSTRUCTION NOISE LEVELS VS. DISTANCE FIGURE 12 N Z O r va O m r 5 o = w LU 3 '* m r 1O m 6 F- N � O N < Z O N O O N 4 Y Q 7 N � O W N w S N ; Y > Q O h N Y Y 6 : adc Q W i �o 0 C � 0 O N E i= m cc m N L C V N Z O m F- N N < O N O O N 4 Y Q N � O W w S N ; > Q O h N Y Q W i high construction noise barriers may also be used where close—in construction work to noise sensitive structures is unavoidable. ;h Page APPENDIX A. REFERENCES (1) "FHWA Highway Traffic Noise Model User's Guide;" FHWA—PD-96-009, Federal Highway Administration; Washington, D.C,; January 1998. (2) Draft Traffic Data and Forecasts for the Proposed Kawailani—lwalani— Ainaola Traffic Signal Improvements Project; Transmittals from The Traffic Manage— ment Consultant; 10/23/97 and 6/29/98. (3) 24—Hour Traffic Counts and Vehicle—Type Classification, Station 18-77, Kawailani Street at Iwalani Street; June 25-26, 1996; Hawaii State Department of Transportation. (4) 24—Hour Traffic Counts and Vehicle—Type Classification, Station 18-77, Kawailani Street at Iwalani Street; August 7, 1996; Hawaii State Department of Transportation. (5) Federal Highway Administration; "Procedures for Abatement of Highway Traffic Noise and Construction Noise;" 23 CFR Chapter I, Subchapter H, Part 772; April 1, 1995. (6) "Noise Analysis and Abatement Policy;" Hawaii State Department of Transportation, Highways Division, Materials Testing and Research Branch; October 1996. (7) 'Title 11, Administrative Rules, Chapter 46, Community Noise Control;" Hawaii State Department of Health; September 23, 1996. Page APPENDIX B EXCERPTS FROM EPA'S ACOUSTIC TERMINOLOGY GUIDE escriptor Symbol Usaqe The recommended symbols for the commonly used acoustic descriptors based on A -weighting are contained in Table 1. As haat acoustic criteria and standards used by EPA are derived from the A -weighted sound level, almost all descriptor symbol usage guidance is contained In Table I. Since acoustic nomenclature includes weighting networks other than "A" and measurements other then pressure, an expansion of Table 1 was developed (Table I1). The group adopted the ANSI descriptor -symbol scheme which is structured into three stages. The first stage indicates that the descriptor is a level (i.e., based upon the logarithm of a ratio), the second stage Indicates the type of quantity (power, pressure, or sound exposure), and the third stage indicates the weighting network (A, B, C, D, E..... ). If no weighting network is specified, "A" weighting Is understood. Exceptions are the A-wefghted sound level and the A -weighted peak sound level which require that the "A" be specified. For convenience in those situations in which on A -weighted descriptor is being compared to that of anther weighting, the alternative col u n in Table 11 permits the inclusion of the "A". For example, a report on blast noise might wish to contrast the LCdn with the LAdn. Although not Included in the tables, it is also recommended that "Llan" and "LepN" be used as symbols for perceived noise levels and effective perceived noise levels, respectively. It is recommended that in their initial use within a report, such terms be written in full, rather than abbreviated. An example of preferred usage is as follows: The A -weighted sound level (LA) was measured before and after the installation of acoustical treatment. The measured LA values were 85 and 75 d8 respectively. Descriptor Nomenclature With regard to energy averaging over time, the term "average" should be discouraged in favor of the term "equivalent". Hence, Loq, is designated the "equivalent sound level". For Ld, Ln, and Lan, "equivalent" need not be stated since the concept of day, night, or day -night averaging Is by definition understood. Therefore, the designations are "day sound level", "night sound level", and "day -night soul level", respectively. The peak soul level is the logarithmic ratio of peak sound pressure to a reference pressure end not the maximum root mean square pressure. while the latter Is the maximum sound pressure level, It Is often incorrectly labelled peak. In that sound level meters have "peak" settings, this distinction Is oast important. "Background ambient" should be used in lieu of "background", "ambient", "residual", or "indigenous" to describe the level characteristics of the general background noise due to the contribution of many unidentifiable noise sources near and far. With regard to units, it is recommended that the unit decibel (abbreviated dB) be used without modlficati on. Hence, DBA, PNde, and EPNdB are not to be used. Examples of this preferred usage are: the Perceived Noise Level (flan was foul to be 75 dg- Lan a 75 d8). This decision was based upon the recommendation of the National Bureau of Standards, and the policies of ANSI and the Acoustical Society of America, all of which disallow any modification of bel except for prefixes indicating its multiples or submultiples (e.g., deci). Noise Impact In discussing noise Impact, It is recommended that "level Weighted Population" (LWP) replace "Equivalent Noise Impact" (ENI). The term "Relative Change of Impact" (RC1) shall be used for comparing the relative differences in LWP between two alternatives. Further, when appropriate, "Noise Impact Index" (NII) and "Population Weighed Loss of Hearing" (PHL) shall be used consistent with CHABA Working Group 69 Report Guidelines for Preparing Environmental Impact Statements (1977). P C% APPENDIX B (CONTINUED) TABLE I A—WEIGHTED RECOMMENDED DESCRIPTOR LIST (1) Unless otherwise specified, time Is In hours (e.g. the hourly equivalent level Is Leq(1)). Time may be specified in non— quantitative terms (e.g., could be specified a Leq(WASH) to mean the washing cycle noise for a washing machine). SOURCE: EPA ACOUSTIC TERMINOLOGY GUIDE, BNA 8-14-78, 771 TERM SYMBOL 1. A -Weighted Sound Level LA 2. A -Weighted Sound Power Level LWA 3. Maximum A -Weighted Sound Level Lmax 4. Peak A -Weighted Sound Level LApk 5. Level Exceeded x% of the Time Lx 6. Equivalent Sound Level Leq 7. Equivalent Sound Level over Time (T) (1) Leq(T) 8. Day Sound Level Ld 9. Night Sound Level Ln 10. Day -Night Sound Level Ldn 11. Yearly Day -Night Sound Level Ldn(Y) 12. Sound Exposure Level LSE (1) Unless otherwise specified, time Is In hours (e.g. the hourly equivalent level Is Leq(1)). Time may be specified in non— quantitative terms (e.g., could be specified a Leq(WASH) to mean the washing cycle noise for a washing machine). SOURCE: EPA ACOUSTIC TERMINOLOGY GUIDE, BNA 8-14-78, 771 APPENDIX B (CONTINUED) TABLE it RECOMMENDED DESCRIPTOR LIST (1) "Alternative" symbols may be used to assure clarity or consistency. (2) Only B -weighting shown. Applies also to C,D,E...... weighting. (3) The term "pressure" is used only for the unweighted level. (4) Unless otherwise specified, time is In hours (e.g., the hourly equivalent level Is Leq(1). T1me may be specified In non -quantitative terms (e.g., could be specified as Leq(WASH) to mean the washing cycle noise for a washing machine. TERM A -WEIGHTING ALTERNATIVE(') A -WEIGHTING WEIGHTING OTHER(2) UNWEIGHTED 1. Sound (Pressure)(3) LA LPA L B, LpB L Level 2. Sound Power Level LWA LWB LW 3. Max. Sound Level L Max L Amax L emax L Amax 4. Peak Sound (Pressure)LApk Lepk Lpk Levet 5. Level Exceeded x% of Lx LAx LBx Lpx the Time 6. Equivalent Sound Level Le L Aeq L Beq Lpeq 7. Equivalent Sound Level (4) Leq(T) LAeq(T) Leeq(T) Lpeq(T) Over Time(T) 8. Day Sound Level L LAd L8d Lpd 9. Night Sound Level Ln LAn LBn Lpn 10. Day -Night Sound Level Ldn LAdn LBdn Lpdn 11. Yearly Day -Night Sound Ldn(Y) LAdn(Y) LBdn(Y) Lpdn(Y) Level 12. Sound Exposure Level LS LSA LSB LSp 13. Energy Average Value Leq(e) LAeq(e) Leeq(e) Lpeq(e) Over (Non -Time Domain) Set of Observations 14. Level Exceeded x% of Lx(e) LAx(e) LBx(e) Lpx(e) the Total Set of (Non -Time Domain) Observations 15. Average Lx Value Lx LAx LBx Lpx (1) "Alternative" symbols may be used to assure clarity or consistency. (2) Only B -weighting shown. Applies also to C,D,E...... weighting. (3) The term "pressure" is used only for the unweighted level. (4) Unless otherwise specified, time is In hours (e.g., the hourly equivalent level Is Leq(1). T1me may be specified In non -quantitative terms (e.g., could be specified as Leq(WASH) to mean the washing cycle noise for a washing machine. APPENDIX C SUMMARY OF BASE YEAR AND FUTURE YEAR TRAFFIC VOLUMES ROADWAY •... CY 1997 •"" CY 2018 (SCH A) CY 2018 (SCH B) LANES AM VPH PM VPH AM VPH PM VPH AM VPH PM VPH Kawailani—Seg b (ES) 484 313 N/A N/A N/A N/A Kawailani—Seg b (WB) 402 ---- 432 ---- N/A ---- N/A ---- N/A N/A ---- Two—Way 886 745 N/A N/A ---- N/A N/A Kawailani—Seg c (EB) 480 314 600 380 600 380 Kawailani—Seg c (WB)392 ---- 375 ---- 495 ---- 465 495 465 Two—Way 872 689 1,095 ---- 645 ---- 1,095 ---- 845 Kawailani—Segd(EB) 990 531 1,060 600 1,060 600 Kawailani—Seg d (WB) 554 ---- 918 ---- —635 --- 1,000 ---- 635 ---- 1,000 ---- Two—Way 1,543 1,448 1,695 1,600 1,695 1,600 Kawailani—Seg a (ES) 772 381 905 480 905 480 Kawailani—Seg a (WB) 525 ---- 599 ---- 655 ---- 745 655 745 Two—Way 1,297 980 1,560 ---- 1,225 ---- 1,560 ---- 1,225 Kuhilani(NB) 57 36 N/A N/A N/A N/A Kuhilani(SS) 6t ---- 112 ---- N/A ---- N/A ---- N/A N!A ---- Two—Way 118 148 N/A N/A ---- N/A N/A Ehehene(NB) 17 7 N/A N/A N/A N/A Ehehene(SB) 11 ---- 14 ---- N/A ---- N/A ---- N/A ---- N/A ---- Two—Way 28 21 N/A N/A N/A N/A Pohakulani—North (NB) 7 24 150 95 150 95 Pohakulani—North (SB) 25 ---- 14 ---- 90 ---- 160 90 160 Two—Way 32 38 240 ---- 255 ---- 240 ---- 255 Pohakulani—Center (NS) 8 5 N/A N/A N/A N/A Pohakulani—Center(SB) 181 — --- 556 ---- N/A— — --------- — N/A— — N/A— — N/A Two—Way 189 561 N/A N/A N/A N/A Pohakulani— South (NB) 26 20 N/A N/A N/A N/A Pohakulani— South (SB)4 ---- 29 ---- N/A ---- N/A ---- N/A ---- N/A ---- Two—Way 30 49 N/A N/A N/A N/A Ainaola (NEB) 467 228 610 295 610 295 Ainaola (SWB) 176 ---- 521 ---- 235 715 235 715 Two—Way 643 749 ---- 845 ---- 1,010 ---- 845 ---- 1,010 Iwalani—North (NB) 449 172 425 160 425 160 Iwalani— North(SB) 132 362 120 315 120 315 Two—Way 561 534 545 475 545 475 Iwalani—South (NB) 128 25 170 40 170 40 Iwalani—South (SB) 28 76 45 100 45 100 Two—Way 156 101 215 140 215 140 APPENDIX 4 AGENCY COMMENTS AND PUBLIC INVOLVEMENT KAWAILANI STREET INTERSECTION IMPROVEMENTS ENVIRONMENTAL ASSESSMENT APPENDIX 4 PUBLIC INVOLVEMENT Comments in Response to Pre -Consultation Stephen K. Yamashiro Mayor June 3, 1998 (gau2ik of 'ti Uii FIRE DEPARTMENT 777 Kilauea Avenue • Mall [ane • Hilo, Hawaii 967204239 (808) 961.8297 • Fax (808) 961.82% � -7Czc Nelson M. Tsuji Fire C/uef Edward Bumatay Deputy fire Cite/ To: Donna Fay K. Kiyosaki, Chief Engineer From: Nelson M. Tsuji, Fire Chief SUBJECT: ENVIRONMENTAL ASSESSMENT, INTERSECTION IMPROVEMENTS AT AINAOLA DRIVE AND KAWAI ANT STREETS. HILO HAWAII We have no comments on any environmental conditions or impacts related to the above -referenced project. We would like to receive a copy of the Draft EA when it is completed. w�- s v.. Fire Chi7 OKAHARA 8 ASSOC., INC. HILO OFFICE Stephen K. Yantashiro .Noun, June 3, 1998 (grrunfv of �tifmii PLANNING DEPARTMENT 25 Aupuni Street, Room 109 • Hilo, Hawaii 967204252 (808) 961-8288 • Fax (808) 961.8742 Mrs. Donna Fay K. Kiyosaki, P.E. Chief Engineer Department of Public Works 25 Aupuni Street Hilo, HI 96720 Dear Mrs. Kiyosaki: Virginia Goldstein Direct", Russell Kukubun Depury D,,,,t,,, OKAHARA & ASSCC., !NC. HILO OFFC3 Preliminary Comments Regarding Preparation of Draft Environmental Assessment for Intersection Improvements at Ainaola Drive and Kaw it ni Streets Hilo nd ni Hilo Hawaii Thank you for your letter dated May 27, 1998, requesting our preliminary comments regarding the preparation of a draft environmental assessment for proposed improvements to Kawailani Street at its intersections with Ainaola Drive-Pohakulani Street and Iwalani Street. We have completed our preliminary review and have the following comment to offer for your consideration. While we support the improvement of these intersections to maximize traffic safety and minimize traffic congestion, the material included with your letter does not clearly indicate the various improvement alternatives being explored. Your letter does state that several alternative intersection designs are being developed. Therefore, we are not able to provide you with any comments specific to the proposed improvements at this time. These alternative designs should be included within the draft environmental assessment. In general terms, we should have no objections should the redesign of these intersections be limited to the installation of traffic signals, the widening of tate roadway, or a combination thereof. However, should there be a need to widen or realign portions of the existing road right-of-way, then the requirements of Chapter 23, Hawai) County (Subdivision) Code must be complied with and the impacts of such widening discussed within the environmental assessment. Mrs. Donna Fay K. Kiyosaki, P.E. Chief Engineer Department of Public Works Page 2 June 3. 1998 Thank you for giving our office the opportunity to comment. We look forward to reviewing the draft environmental assessment. Should you have any questions, please contact Daryn Arai of this office at 961-8288. Sincerely VIRGIMA GOL TEIN Planning Directo DSA:cjf f.\wp60\cztn\Ch343\LD P WO l .dsa z-7 �. United States Department of the Interior y V s a ; e ' FISH AND WILDLIFE SERVICE Pacific Islands Ecoregion 300 Ala Moana Blvd, Rm 3-122 Box 50088 Honolulu, HI 96850 In Reply Refer To: EAS Donna Fay K. Kiyosaki, P.E. County of Hawaii Department of Public Works 25 Aupuni Street, Room 202 OKAHARA s As_OC,.. INC. Hilo, Hawaii 96720-4252 w1LO CFF;Cc RE: Environmental Assessment, Intersection Improvements at Ainaola Drive and Kawailani Streets, Hilo, Hawaii Dear Ms. Kiyosaki: Thank you for the opportunity to review and comment on your letter dated May 27, 1998, concerning the Environmental Assessment (EA) for intersection improvements at Ainaola Drive and Kawailani Streets in Hilo, Hawaii. The County of Hawaii Department of Public Works, in conjunction with the Hawaii State Department of Transportation, and the Federal Highway Administration's Hawaii Division is beginning a design for a safety-related intersection project in Hilo. The proposed project would improve the two closely spaced intersections of Kawailani Street with Iwalani Street and Ainaola Drive with Pohakulani Street. The intersections have a greater than average rate of accidents and are subject to congested traffic conditions during morning and afternoon peak hours. The purpose of the project is to redesign the intersections in such a way as to maximize traffic safety and minimize peak hour traffic congestion. No threatened or endangered species are known to occur in the vicinity of the proposed intersection improvements and no significant adverse impacts to fish and wildlife resources are expected to result from the proposed project. The Fish and Wildlife Service appreciates the opportunity to comment on the proposed intersection improvements. If you have questions regarding these comments, please contact Fish and Wildlife Biologist Elizabeth Sharpe by telephone at 808/541-3441 or by facsimile transmission at 808/541- 3470. Sincerely, Brooks Harper Field Supervisor Ecological Services cc: NNIFS-PAO, Honclulu USEPA-Region IX, San Francisco ![NJ . IN 1. CAT[TNIO GOV[RNOA OF NAWM v TY July 10, 1998 ,A • •�• r tA•I STATE OF HAWAII DEPARTMENT OF LAND AND NATURAL RESOURCES STATE HISTORIC PRESERVATION OMSM 33 SOUTH KING STREET. 6TH FLOOR HONOLULU. HAWAII 968/3 JUL 1 31998 Ms. Donna Fay K. Kiyosaki, P.E. County of Hawaii Department of Public Works 25 Aupuni Street, Room 202 Hilo, Hawaii 96720 Dear Ms. Kiyosaki: y — .- '7 AIICMA(L 0. WILSON, CNAIAABLFON i IOAAO OF OANO NATL A(SOL C[S OEIFU Y O, I V T COLOMA.AGAAAN AO U.Tr [O(Va OPMINT MOCAMA AQUATIC AIWO C[/ CONsavAnp[ ANO DIVIAONM[NTAI AFFAAS CONSEAVATION ANO A[SOVAC[S wOACOApr CONV(YANC[S FOAISTAY ANO WLDUF[ HISTONC MISGVATION OMMON LAND MµAODADer ITATIE AAAI WAIN ANO LANO ON(lOPMOIT LOG NO: 21939 DOC NO: 9806MS02 SUBJECT: Section 106 Review: Historic Preservation Concerns for Environmental Assessment, Intersection Improvements at Ainaola Drive and Kawailani Streets Waiakea Homesteads, South Hilo, Hawaii TMK: (3)2-4-19: roadway Thank you for the opportunity to review this project. As Federal Highway Administration funds are involved, a Section 106 review is required to remain in compliance with the National Historic Preservation Act of 1966, as amended. A sight inspection to the project area was made by Historic Preservation Division staff archaeologist Marc Smith on June 17, 1998. Following this inspection, he concurs with your assessment that the project area has been modified in the past, and it would be very unlikely to have any significant historic sites present in the project area. We believe that the proposed action will have no effect on significant historic sites. If you should have any further questions please call Pat McCoy at 587-0006 (Honolulu), or IkAarc Smith at 933-4482 (Hi!o). Aloha, o. 0. Michael D. Wilson, Chairpe on nd State Historic Preservation r MS:amk C. Okahara & Associates, Inc. Ron Terry, Geo Metrician Associates JUL 17 1448 OKAHAKA; ASSOC., INC, HILO OFFICE APPENDIX 5 LIST OF PROPERTIES AFFECTED BY RIGHT-OF-WAY TAKING Alternate 26 Alternate IA Alternate 113 Alternate 2A 2-4-02:001 ✓ 2-4-02:128 ✓ ✓ ✓ 2-4-12:043 ✓ ✓ ✓ 2-4-12:097 ✓ ✓ ✓ 2-4-15:027 ✓ ✓ ✓ 2-4-15:029 ✓ ✓ ✓ 2-4-15:030 ✓ ✓ ✓ 2-4-15:032 ✓ ✓ ✓ 2-4-15:034 ✓ ✓ ✓ 2-4-15:119 ✓ ✓ ✓ 2-4-15:120 ✓ ✓ ✓ 2-4-15:225 ✓ ✓ ✓ 2-4-19:011 ✓ ✓ ✓ 2-4-19:012 ✓ ✓ ✓ 2-4-19:013 ✓ ✓ ✓ 2-4-19:025 ✓ ✓ ✓ 2-4-19:035 ✓ ✓ ✓ 2-4-19:060 ✓ 2-4-19:073 ✓ 2-4-19:075 ✓ ✓ ✓ 2-4-19:087 ✓ ✓ ✓ 2-4-19:092 ✓ 2-4-19:093 ✓ ✓ ✓ 2-4-19:126 2-4-19:127 ✓ ✓ ✓ 2-4-19:128 ✓ �% ✓ 2-4-19:158 ✓ Alternate 26