Passengers per hour per direction

Passengers per hour per direction (p/h/d),[1] passengers per hour in peak direction[2] (pphpd) or corridor capacity[3][4] is a measure of the route capacity of a rapid transit or public transport system.

The corridor capacity in the passenger transport field refers to the maximum number of people which can be safely and comfortably transported per unit of time over a certain way with a defined width.

Many public transport systems handle a high directional flow of passengers— often traveling to work in a city in the morning rush hour and away from the said city in the late afternoon.

To increase the passenger throughput, many systems can be reconfigured to change the direction of the optimized flow.

This gives rise to the measure of the peak-flow rather than a simple average of half of the total capacity.