Public Transport ETA can generate automatic transfer alerts. Three use cases are considered:
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Trip-Trip transfer alerts
The system estimates the time to accomplish the transfer between two trips (trip_from, trip_to) at defined stops (stop_from, stop_to). The system raises an alert if the transfer time computed according to the real-time information exceeds the planned schedule by a specified threshold.
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Trip-route transfer alerts
The system estimates the time to accomplish the transfer between a trip (trip_from) and a route (route_to) at defined stops (stop_from, stop_to). The system raises an alert if the transfer time computed according to the real-time information exceeds the planned schedule by a specified threshold.
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Route-route transfer alerts
The system evaluates the time to accomplish the transfer between two routes (route_from, route_to) at defined stops (stop_from, stop_to). The system raises an alert if the transfer time computed according to the real-time information exceeds the planned schedule by a specified threshold.
An alert is raised when the following condition is satisfied:
| Variable | Description |
|---|---|
| trs | Transfer time computed according to the planned schedule |
| trr | Transfer time computed according to the real-time information |
| a | Alert threshold |
| tmin | Minimum time to arrive from stop_from to stop_to |
| Time of the next arrival of the trip_from at stop_from | |
| Time to the next arrival of a trip of trip_to at stop_to after the time instant given by: | |
| Arrival time of trip_from at stop_from |
The services are made available externally by dedicated APIs (→ Public transport API).