GTFS-RT trip ids not found in static GTFS

[Edmund Fung]

Hello!

I am noticing that the subway GTFS static data does not include the trip ids found in the realtime data. I am using the regular and supplemental subway GTFS and the various MTA realtime apis. Am I missing another data source?

For example, the trip_id `000200_E..N` is returned in the GTFS-RT for MTA ACE but `000200_E..N` is not found in the regular nor supplemental static GTFS. 

This seems to affect all subways.

Thanks!

[Sunny]

Please see https://api.mta.info/GTFS.pdf and the extension protobuf file located at https://raw.githubusercontent.com/OneBusAway/onebusaway-gtfs-realtime-api/master/src/main/proto/com/google/transit/realtime/gtfs-realtime-NYCT.proto

In short, because the schedule operated on a day to day basis and the static schedule can sometime differ dramatically, the two feeds are to be used somewhat independently and are not intended to be matched on a trip by trip basis. In short, you should treat the trips in the realtime feed as the entirety of the service operating in the TripReplacementPeriod. Any trips in the static GTFS that don't appear aren't actually running, any trips that don't appear in the static GTFS are to be treated as ADDED.