Green Line Trip Ids

[Paul Harrington]

Hi Guys,

Using GTFS, I'm looking at setting up a departures board for North Station. In a list of next departures (of all transport types) for the station I pick up the likes of the following from the SCHEDULE: 

FINER   [2017-02-01 05:30:28]   TripId=[32265402] Departure=23:33:00 Arrival=23:33:00 Date=20170131 Direction=INBOUND RouteType=LIGHTRAIL HeadSign=[Lechmere] RouteShortName=[E] RouteLongName=[Green Line E] RouteColor=427B1D RouteTextColor\

=FFFFFF StopSequence=630 [Wheelchair access] PickUp=[(0) Regular] DropOff=[(0) Regular]

However trip 32265402 or any other green line trip id never seems to be referenced in either TripUpdates or VehiclePosition RTD so there is no real time data for those trips and I can only work of the schedule.

However, when scanning the Vehicle Position RTD  for any trips with North Station as their next scheduled stop I come across the likes of trip id 1649_0 on the green line which is not found anywherte in the schedule:

FINER   [2017-02-01 05:30:28]   Processing Vehicle Position [TRIP id=1649_0 stopId=70206 stopSequence=20, routeId=Green-E status=STOPPED_AT, location=(-71.060402,42.365429), timestamp=1485923372000(2017-01-31 23:29:32)]

FINER   [2017-02-01 05:30:28]     Retrieving schedule info for [tripId=1649_0 stopId=70206]

FINER   [2017-02-01 05:30:28]     Database retrieval occured in 0.000 seconds

WARNING [2017-02-01 05:30:28]     No schedule available for trip 1649_0 with Vehicle Position entry

Later on when I'm filtering my list of next departures I drop this trip because there is no scheduled or estimated time and I cannot really do anything useful with it:

INFO    [2017-02-01 05:30:28]   Removing(ETA 1485923428 secs in past, 0 allowed) Trip=[1649_0 ] Est=[1969-12-31 19:00:00 (    min)] Sch=[1969-12-31 19:00:00] Stat=[STOPPED_AT 56s] Loc=[20 20] SchRtdVeh=[001] HeadSign=[] Route=[ ] Occ=[] S\

topInfo=[70206 Pass p(0) d(0)]                                                            

Am I correct in assuming that what I see in the schedule and vehicle position RTD are the same trips but that they are using different trip IDs ? And if this is the case are there any plans to change the vehicle position trip ids to match the schedule ?

Thanks Paul.

[Developer at MBTA]

Hi Paul,

Currently the trip IDs on the Green Line real-time data are arbitrary integers that do not correspond to trip IDs in the schedule data. Matching trip IDs for Green Line real-time is part of our road map (see this post under "Subway prediction improvements"), although we do not currently have a firm date for deployment.

Sincerely,

Developer@MBTA