This program processes MTA Subway GTFS-RT feeds, converts them to standard GTFS-RT, and publishes a consolidated TripUpdate feed at a new endpoint. If possible, TripUpdates from the RT feed are matched to static GTFS trips and RT IDs are replaced by matched static trip IDs.
Build jar:
mvn package
Get NYC Subway GTFS from MTA developer downloads (login through mta.info/developers and sign the agreement first):
wget http://web.mta.info/developers/data/nyct/subway/google_transit.zip
Run the program:
java -jar nyct-rt-proxy-1.0-SNAPSHOT-withAllDependencies.jar --config config.txt
Here is an example config.txt. Uncomment the cloudwatch.* values to send metrics to Cloudwatch (disabled otherwise):
NYCT.gtfsPath=/path/to/google_transit.zip
NYCT.key=
tripUpdates.url=http://localhost:8001/tripUpdates
#cloudwatch.namespace=
#cloudwatch.accessKey=
#cloudwatch.secretKey=
The following parameters are defaults, but can be overridden by adding to config.txt:
NYCT.feedIds=["1", "2", "11", "16", "21"]
NYCT.routeBlacklistByFeed={"1": ["D", "N", "Q"]}
NYCT.routesNeedingFixup=["SI", "N", "Q", "R", "W", "B", "D"]
NYCT.realtimeToStaticRouteMapByFeed={"1": {"S": "GS"}}
NYCT.latencyLimit=300 # ignore feed if its timestamp is more than 300s in the past
NYCT.lateTripLimitSec=3600 # match RT trip to static trip with scheduled departure up to 3600s before RT trip
NYCT.refreshRate=60
- There can be duplicate trip IDs in the published feed, because TripUpdates without an exact origin-departure time match are matched to the closest static trip in the past. We cannot remove duplicates without adding state to the matching algorithm.
- StopTimeUpdates which do not correspond to stop times in the matched trip are removed. This means that if an express trip is running local, local stops will not be propagated.
See MTA's list of feeds.
| Feed ID | Routes | Notes |
|---|---|---|
| 1 | 1,2,3,4,5,6,GS | May include a subway path identifier at the end of trip IDs. |
| 2 | L | |
| 11 | SI | |
| 16 | N,Q,R,W | Intermittent connections. |
| 21 | B,D | Southbound trips on D may be separated at mid-line relief points. |
Routes in feeds 11, 16, and 21 require "fixup" ie start date must be reformatted and directions must be added to stop IDs.