How Transportation Operators Determine Their Passenger Flows

The passenger flow is defined as the number of trips made in a given period of time between two points of a transport network. For example, between stop A and stop B of line L, the number of trips made on a given day is X; in other words the movement of X passengers. This information is then used to build up what are called “origin-destination matrices” showing the number of trips made in this time period for each pair of stops in the network.

The passenger flow enables operators to correctly forecast how demand will react to changes in supply. Thanks to this knowledge, the operator will be able to make a series of decisions:

• Optimize scheduling to ensure the service meets the demand in given time bands
• Modify headways to avoid empty trips or, on the contrary, a glut of vehicles at the same time
• Decide which lines and routes have the highest demand; these may then be reinforced or the headway cut down in other lower-demand routes
• Modify the network, adding or removing lines or stops.

Intelligent transportation systems help operators find out their passenger flows. One of the most important devices for this purpose, probably the most widely used up to now, is the passenger counting device. These devices are fitted on vehicle doors to determine the number of passengers getting on and off at each stop and therefore vehicle occupancy. From this information the number of trips between each two points of the network can easily be deduced. These systems are not 100% accurate but are good enough for drawing up an origin-destination matrix where the ridership figure is not crucial.

A second method widely used today taps into the bus passengers' Wi-Fi signal. The bus’ Wi-Fi access point is capable of reading the users’ cell phone MAC address; this then allows us to track each passenger’s ride from the moment of getting on the bus to the moment of getting off. This method respects passenger privacy at all times; only the MAC address is used rather than the telephone number or other personal data. One of the most important initiatives of this time has been set up by Barcelona’s Metropolitan Transport Service (Transports Metropolitans de Barcelona: TMB) with GMV’s help.

Author: Isidro Prieto