If any of this blog’s readers will be attending OSCON July 25-29th in Portland, I suggest you check out the session being led by my codeveloper, Chris Smith, leader and founder of the Transit Appliance project, citizen activist and blogger extraordinaire. He’ll be talking about the open-source roots of the Transit Appliance project, and how the use of open data, hardware and software allows us to create arrival displays that are “disruptively low cost.” More information is available on the official page for the talk.

As a part of the Transit Appliance Project, I’ve been evaluating what transit agencies have real-time data; here’s a (non-exhaustive) list, focused primarily on U.S. agencies (note: these are only agencies that provide an API, not any agency with a real-time feed):

• TriMet, Portland, OR, custom JSON$$-P$$ feed, XML may also be available. GTFS-realtime is also available.
• San Francisco Muni, via NextBus.
• Bay Area Rapid Transit (BART), San Francisco, CA, custom XML feed. Their Google Group is very responsive and helpful. GTFS-realtime is also available.
• AC Transit, Oakland, CA, via NextBus.
• Los Angeles Metro, both via NextBus and a custom XML API.
• Unitrans, Davis, CA, via NextBus. Their GTFS is hosted by Sacramento RT.
• MBTA, via NextBus. They have a GTFS at http://www.eot.state.ma.us/developers/ that has stop ids to match NextBus. They have a trial up for rail arrivals.
• Transport for London (TfL), custom XML API.
• Washington Metropolitan Area Transit Authority (WMATA), custom XML/JSON$$-P$$ API; has real time arrivals for rail, but only positions for buses (no arrivals).
• DC Circulator, via NextBus. I couldn’t find any public GTFS.
• Chicago CTA, custom XML API for buses, no arrival data for trains yet.

I know that there are a ton that aren’t on here; as I do more research, I’ll put more up.