In a mesoscopic simulation, when pedestrians enter the model, they walk to the closest section and then use that section to walk in free flow without considering any delays, i.e.: interactions between pedestrians and vehicles or delays in traffic lights. Some sections may be set as Not Allowed for all or some pedestrian types (Section > Main > Prohibited Vehicle and Pedestrian Types). In this case, pedestrians will discard the option of entering this section and they will walk to the next closest section. For more information, see the Mesoscopic Pedestrian Simulator.
In a microscopic simulation, a pedestrian may be forced to calculate a new path while on-trip if the transit vehicle that they planned to board has no spare capacity when serving the transit stop. In a mesoscopic simulation there is no rerouting possible, so in the same situation, the pedestrian will wait until the next transit vehicle of the same line arrives.
The cost of the different path options is evaluated at the beginning of the trip as described below. The minimum cost option depends on the exact departure time of the trip and on the transit schedule: for example, for the same OD pair and time slice, a pedestrian departing earlier may find it more convenient to walk to their destination rather than waiting for a long period of time at a transit stop, while one departing closer to the time at which a bus goes by will chose to take transit.
A. Only Walk
The cost of a walk-only path is equal to the walking time (seconds) from origin to destination. This is calculated based on the Mean Walking Speed of the Pedestrian Type and the shortest distance within the same pedestrian area considering obstacles. In a mesoscopic simulation, pedestrians do not use any obstacles while walking but the shortest distance to the closest section.
B. Walk and Transit
The cost of a path that uses transit is calculated by adding the cost components below:
1. Walking cost (in seconds): This is the time spent walking during the entire trip. This includes walking from the origin to the first transit stop, from the last transit stop to the destination, and between transit stops in case the path involves a transfer through different stops.
2. Waiting cost (in seconds): This is the time spent waiting at a transit stop. This cost is calculated subtracting:
a. The arrival time of the transit vehicle at the boarding stop, which is calculated based on:
- The departure times of this line according to the timetable
- The free flow travel time of the transit vehicle to reach the stop
- The sum of the scheduled dwell times at all previous stops according to the timetable
b. The arrival time of the pedestrian at the stop, which is calculated based on:
- The departure time of the pedestrian agent from the origin
- The walking time to reach the transit stop from the origin
3. Fare cost (cost): The fare is a sum of:
- A Flat Fare if the option Apply Flat Fare is activated in the dynamic experiment, e.g. €2.50.