Baltimore civic hackers freed bus data MTA priced at $600K — it was already streaming

In February 2015 the Maryland Transit Administration launched a basic web app for tracking Baltimore buses — while telling developers that opening the data to third-party apps would cost roughly $600,000: its 25-year-old CAD/AVL system did not emit the GTFS format transit apps need. The agency's own app was a byzantine web page without geolocation, and the data behind it stayed locked away from Google Maps and the “app economy” the agency's press releases liked to invoke.

Within days, geo-data developer and open-data advocate Chris Whong opened the web app's network traffic and found it polling MTA servers every 10 seconds for JSON — encoded in GTFS, the exact format developers were told was too costly to produce. A few hours of trial and error confirmed the feed; with a small team of civic hackers he assembled a framework that let any application pull the data for free, demonstrated it with a live tracking site on Heroku, and posted everything on GitHub.

Adoption was immediate. Montreal developer Transit App used the feed to launch Baltimore real-time tracking “with just an afternoon of work — $600,000 under budget,” generating its own predicted bus arrivals and comparing them against the MTA's tracker to verify accuracy.

The costly part — formatting CAD/AVL output — had already been solved once for the agency's own web app, so a machine-readable copy existed that any browser could read.

Publishing the scraped feed as open-source infrastructure turned one developer's hack into something commercial developers could adopt the same week.

The agency's cost estimate was never tested against the cheap path: its own front door.

Before accepting a six-figure estimate for opening data, check whether the data already flows to a system you can reach; the expensive part is often already built for the agency's own use.

The MTA responded to Transit App’s post by explaining the $600,000 figure reflected converting its CAD/AVL data to real-time GTFS before the web interface existed, saying a brand-new real-time GTFS system was already in the works, and announcing engineers had spent weeks finding a way to move the data into a secure environment where third-party developers could safely use it — adding, “civic hackers have helped us speed this announcement up.” Ars noted the underlying data stayed limited: buses report over radio from GPS, so positions drop out until MTA fixed the feed.