Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the
route capacity
Route capacity is the maximum number of vehicles, people, or amount of freight than can travel a given route in a given amount of time, usually an hour. It may be limited by the worst bottleneck in the system, such as a stretch of road with few ...
of a
rapid transit
Rapid transit or mass rapid transit (MRT), also known as heavy rail or metro, is a type of high-capacity public transport generally found in urban areas. A rapid transit system that primarily or traditionally runs below the surface may be c ...
or
public transport
Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typic ...
system.
Definition

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.
The corridor capacity does not measure the number of vehicles which can be transported over such way, since the nuclear objective of passenger mobility is to transport passengers, not vehicles.

In terms of quantities defined within the
International System of Units, the corridor capacity may be measured in units of
, ''i.e.'', the maximum number of passengers per second per meter of the corridor's width.
An approximately equivalent concept in physics is
volumetric flux
In fluid dynamics, the volumetric flux is the rate of volume flow across a unit area (m3·s−1·m−2).
Volumetric flux has dimensions of volume/(time*area). The density of a particular property in a fluid's volume, multiplied with the volumetri ...
.
Directional flow

Many public transport systems handle a high directional flow of passengers— often traveling to work in a
city
A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be de ...
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.
A common example is a
railway
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in Track (rail transport), tracks. In contrast to road transport, where the ...
or
metro station
A metro station or subway station is a station for a rapid transit system, which as a whole is usually called a "metro" or "subway". A station provides a means for passengers to purchase tickets, board trains, and evacuate the system in the ...
with more than two parallel
escalator
An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horiz ...
s, where the majority of the escalators can be set to move in one direction.
This gives rise to the measure of the peak-flow rather than a simple average of half of the total capacity.
See also
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References
{{transport-stub
Public transport
Temporal rates
Transportation planning
Units of temporal rate