Question

Volume of 1200 vph is observed at an intersection approach, Find the peak flow rate within the hour for the peak-hour factors:

1.0
0.90
0.80
0.70
Plot and comment on the results

Answer 1

The peak flow rate is found by dividing the volume of 1200 vph by the peak-hour factor (PHF). As the PHF decreases, the peak flow rate increases, indicating more concentrated traffic flows.

Step-by-step explanation:

The question is asking how to find the peak flow rate within the hour for an intersection approach with a volume of 1200 vehicles per hour (vph), given different peak-hour factors (PHF). The peak flow rate can be determined using the formula:

Peak Flow Rate = (Volume / PHF)

• For PHF = 1.0, Peak Flow Rate = 1200 vph / 1.0 = 1200 vph
• For PHF = 0.90, Peak Flow Rate = 1200 vph / 0.90 ≈ 1333 vph
• For PHF = 0.80, Peak Flow Rate = 1200 vph / 0.80 = 1500 vph
• For PHF = 0.70, Peak Flow Rate = 1200 vph / 0.70 ≈ 1714 vph

The results show that as the PHF decreases, the peak flow rate increases. This implies that for a fixed volume, a lower PHF indicates a more concentrated flow of traffic during the peak hour, requiring potentially more robust traffic management solutions.