NYC Subway RT shim

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.

Usage

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

config.txt example

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.gtfsAgency=MTASBWY # if running with buses, override the agency/feed ids by modifying the input gtfs agency_id and adding this option.  Default MTA NYCT
NYCT.feedIds=["1", "2", "11", "16", "21"]
NYCT.routeBlacklistByFeed={"1": ["D", "N", "Q"]}
NYCT.realtimeToStaticRouteMapByFeed={"1": {"S": "GS", "5X": "5"}}
NYCT.addToTripReplacementPeriodByRoute={"6": "6X"}
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
NYCT.retryDelay=5

Known issues

• 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.

Feed/route reference

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.

The following conditions will be automatically fixed:

• Invalid TripDescriptor.start_date values (format YYYY-MM-DD HH:MM:SS rather than YYYYMMDD)
• Stop IDs missing direction of travel