Unreferenced Trips in TripUpdates

[Paul Harrington]

Just noticed that log files got quite large due to loads of entries like

WARNING [2017-10-16 00:05:51] Not deriving StopTimeInformation for trip[983ECF15] from stop[140 70078] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:05:51] Not deriving StopTimeInformation for trip[983ECF15] from stop[140 70078] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:05:51] Not deriving StopTimeInformation for trip[983ECF15] from stop[140 70078] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:05:51] Not deriving StopTimeInformation for trip[983ECF15] from stop[140 70078] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:05:51] Not deriving StopTimeInformation for trip[983ECF15] from stop[140 70078] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:05:51] Not deriving StopTimeInformation for trip[983ECF15] from stop[140 70078] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:06:22] Not deriving StopTimeInformation for trip[983ECEE5] from stop[40 70069] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:06:22] Not deriving StopTimeInformation for trip[983ECEE5] from stop[40 70069] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:06:22] Not deriving StopTimeInformation for trip[983ECEE5] from stop[40 70069] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:06:22] Not deriving StopTimeInformation for trip[983ECEE5] from stop[40 70069] as no arrival delay specified and error processing scheduled arrival time

WARNING [2017-10-16 00:06:22] Not deriving StopTimeInformation for trip[983ECEE5] from stop[40 70069] as no arrival delay specified and error processing scheduled arrival time

These trips do not seem to exist in the schedule and I throw a warning as I try to derive times for stops further down the line but they don't specify a delay and I cannot get the scheduled time

for the trip to work out the delta, hence the warning.

These messages  appeared for several days but stopped suddenly at 00:06 October 16th. I've seen them before (and will probably see them again) and was wondering what they are ?

If they are likely to persist then I need to log them at a different granularity so logs don't eat disk space.

[Developer at MBTA]

Hi Paul,

These "added trips" result from the fact that we can't always match up the service that we run perfectly with the GTFS schedule. In particular, on weekends when we are running the Longfellow Bridge shuttles, we generally direct Red Line train operators to "run as directed" rather than following a pre-set schedule. This means that they follow instructions from dispatchers and officials, which may (and generally does) mean that we run additional trips that are not found in GTFS. In the future we hope to improve the correspondence between the GTFS scheduled trips and the service that is actually run during shuttles, but there will always be situations where we cannot match a particular train to a GTFS scheduled trip, and therefore we recommend that you be prepared to handle these without disrupting your logging too much.

Sincerely,

Developer@MBTA