2015 Google Summer of Code Ideas

This page hosts ideas for the 2015 Google Summer of Code program, as discussed on the mailing list.

• GTFS-realtime validation tool - GTFS and GTFS-realtime have become dominant formats for open data in the transit industry. While the GTFS format has a GTFS Feed Validator, no such open-source tool currently exists for GTFS-rt. Due to the implementation details of the GTFS-rt specification, the GTFS-rt spec itself does not provide strong guidance for what data fields should be populated for particular use cases of the data. This proposal would implement a tool that takes a GTFS and GTFS-rt feed as input, and examines the GTFS-rt feed to determine if it properly meets GTFS-rt best practices, both those explicitly listed in the spec and those based on the needs of consuming applications. Sample rules to validate include:

  • stop_time_updates for a given trip_id must be sorted by increasing stop_sequence (this should always be enforced whether or not the feed contains the stop_sequence field) (failure)
  • Frequency-based trip_updates must contain trip_id and start_time (failure)
  • Timestamps should be populated for all elements (warning)
  • All timestamps must be in POSIX time (i.e., number of seconds since January 1st 1970 00:00:00 UTC) (failure)
  • vehicle_id should be populated in trip_update (warning)
  • If both vehicle positions and trip updates are provided, VehicleDescriptor or TripDescriptor values should match between the two feeds (warning)
  • If only delay is provided in a stop_time_update (and not a time), then the GTFS stop_times.txt must contain arrival_times and/or departure_times for all stops referenced in the GTFS-rt feed (i.e., not just timepoints) (failure)

• OpenTripPlanner for Android - Many new enhancements could be implemented for this open-source Android app, including:

  • Implement real-time turn-by-turn navigation for transit, as discussed in issue 297
  • Add support for the Open Source Routing Machine (OSRM) as a new trip planning engine, as discussed in issue 409
  • Add weather information for destination, as discussed in issue 448
  • Update the app to the new Android Material Design concepts, as discussed in issue 449
  • Update the app to work with the newest OTP server master branch REST API (I'm not sure if this is currently working or broken)
  • Integrate with OneBusAway Android for better shortcuts to real-time transit information, as discussed in issue 21-comment