What does the Peak Hour Factor (PHF) formula relate to?

The Peak Hour Factor (PHF) is specifically related to the measure of traffic flow during the highest volume hour of traffic. The formula for calculating the PHF helps to understand how the traffic volume during that hour compares to the peak flow rate observed during the period.

The correct answer is grounded in the concept that the actual hourly volume is assessed in relation to the peak flow rate. By evaluating the actual hourly volume divided by the peak rate flow, the PHF provides insights into the distribution of traffic flow during the peak hour. A higher factor indicates smoother flow during that time, while a lower factor can suggest considerable fluctuations or congestion, highlighting the variability in traffic volumes.

When examining factors that impact traffic and roadway capacity, it is crucial to understand the relationship between actual traffic volumes and the peak flow rate to enhance transportation planning and traffic management strategies.