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Sub-problem 3a: Shenendehowa Campus AM & PM peak - Existing Conditions

Peak Hour Factor 
The peak hour factor (PHF) accounts for variations in flows that occur during the heaviest hour of traffic. If the volume for the hour is 800 vehicles and the heaviest volume during any one 15-minute period is 250 vehicles, then the peak hour factor is 0.80 (800/(4*250)). When you input the hourly volumes and the peak hour factor, you will evaluate the conditions that exist during the peak 15 minutes, the time when the facility is most heavily loaded.

We can use the highly peaked flows at the entrance to the Shenendehowa campus to show how the peak hour factor works and the effect it has. Using data for this intersection will show how the typical method for applying the peak hour factor might or might not lead to the right assessment of the performance conditions in some situations.

Traffic engineers hold different perspectives on the peak hour factor. Some compute values for each clock hour (3-4, 4-5, etc.). Some consider each sequence of four 15-minute time periods and use the sequence with the maximum total volume for the peak hour factor. Some predicate PHF calculation on the sequence of 15-minute time periods that has the maximum flow for the movement, others, the maximum total intersecting volume for the intersection. Still others focus on demand, not volume as the basis for computing the PHF. What do you do? What do you think should be done if the data were available? 

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