TripUpdates and Rail

[Paul Harrington]

Hi,

Yesterday evening at 23:30 I came across trip CR-Weekday-Fall-16-431 in the vehicle position RTD which is indicating that it had not left the station yet:

FINE    [2017-02-01 05:30:28] Retrieving vehicle position information for any vehicles with stop place-north as their next stop

FINER   [2017-02-01 05:30:28]   Processing Vehicle Position [TRIP id=CR-Weekday-Fall-16-431 stopId=North Station stopSequence=1, routeId=CR-Fitchburg status=STOPPED_AT, location=(-71.075417,42.374439), timestamp=1485923269000(2017-01-31 2\

3:27:49)]

FINER   [2017-02-01 05:30:28]     Retrieving schedule info for [tripId=CR-Weekday-Fall-16-431 stopId=North Station]

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

However at 11:30:28 there was no trip update information for it and with a scheduled time of 22:40 I made the decision it was gone and dropped it (the estimated time takes the value of the scheduled time in the absence of a trip update):

INFO    [2017-02-01 05:30:28]   Removing(ETA 3028 secs in past, 0 allowed) Trip=[CR-Weekday-Fall-16-431 0] Est=[2017-01-31 22:40:00 (    min)] Sch=[2017-01-31 22:40:00] Stat=[STOPPED_AT 159s] Loc=[1 1] SchRtdVeh=[101] HeadSign=[Wachusett]\

 Route=[RAIL Fitchburg Line] Occ=[] StopInfo=[North Station Orig p(0) d(1)]

 

After this there would be another trip update with an estimated time in the future and I would show it and this show/drop pattern continued. Eventually after 00:02:57 there were no more trip updates and at 00:16:42 the vehicle position feed no longer suggested it was at the stop.

 

This is something I see a fair bit of. I'm trying to figure out if it is a bug in my implementation or if there is a known issue with rail trips being toggled in and out of trip updates ? 

If I were to have prioritized the vehicle position feed I would have showed it continuously up until 00:16:42.

A second question though is why was there such a long time gap between the last trip update indicating it finally left the station at 00:02:57 and the vehicle position feed not suggesting it was on its way until 00:16:42 ?

Paul.