COM 0649.004 2002-2004 - Laserfiche WebLink

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downhill and uphill lanes of Nani Kailua Drive about 150 feet mauka of the subject intersection. This distance is sufficiently far from the new stop sign to avoid the effects of braking for the stop control sign. Traffic surveyors positioned themselves on the road shoulder so that they could see oncoming vehicles cross both lines. Two traffic surveyors were used, one for each direction of travel. With stop watches, the traffic surveyors noted the time (in hundredths of seconds) for a vehicle to travel between the two lines and wrote the time on a paper form, one sheet for every 30 minute interval. The traffic surveyors were instructed to record as many vehicles as best they could, but they did not have to record each vehicle since spot speed studies do not require that each vehicle be surveyed. Also, they were to record only the first car in a queue of vehicles, since the following vehicles' speeds would be affected by the first vehicle. The surveyors reported that they counted almost every vehicle that passed by. The spot speed surveys were taken from 9:30 A.M. to 12 noon, and from 1:00 to 3:30 PM, for both survey days. Spot speed surveys are generally taken in off peak periods when traffic is generally not affected by traffic congestion. Traffic flow during peak traffic periods are generally affected by congestion and are normally not surveyed. The collected travel times were then input into Excel spreadsheets by direction of travel and by 30 minute intervals. The travel times within each interval were then sorted into descending order (slowest to fastest). For each travel time sample, the formula 6000/ (hundredths of seconds) was used to convert the travel time into speed (miles per hour, mph). The following statistics were generated for each half hour interval and the entire day's sample: o number of samples, o average speed, o standard deviation, o minimum speed, and o maximum speed. 10.