Description
Another key feature of the apps is their accuracy. Hodge said collecting the data for each city is “challenging and complicated,” and uses information from a variety of sources like city public transit organizations, Open Street Map, user feedback, and crowdsourcing. For its New York City apps Embark will even travel to New York to see how long it takes to walk between Subway transfers.
SOURCE LINK to the full article:
http://www.gottabemobile.com/2012/09/21/embark-helps-make-public-transit-easy-in-ios-6/