I am working with historic data collected from the SiriVehicleMonitoring endpoint of the Siri API and am seeing that more than one vehicle using the same trip ID on a given service date is quite common... Here is an example:
Service Date: Feb 1, 2021
For all of the unique trip IDs logged on the Bx19 route with service date Feb 1, 2021:
- ~82.23% were logged by 1 vehicle
- ~14.46% were logged by 2 different vehicles
- ~2.48% were logged by 3 different vehicles
- ~0.41% were logged by 5 different vehicles
- ~0.41% were logged by 8 different vehicles
Trip ID: MTA NYCT_WF_P1-Weekday-094900_BX19_313
I picked one trip ID that was logged by multiple vehicles to examine more closely: MTA NYCT_WF_P1-Weekday-094900_BX19_313. That trip ID is logged by 3 different vehicles. You can see the temporal overlap in logging in the figure below (data was collected at approximately 1 min intervals).
Here are the vehicle locations corresponding to those records:
You can see that 2 vehicles (293 and 295) share the same trip ID for a substantial amount of time (~1 hr), whereas the 3rd vehicle (674) logs that trip ID only briefly.
Is this the sort of issue that others are seeing?