I am trying to find a list of all public transportation/transit locations like subway stations, airports, bus terminals and bus stops for USA. Only major transit locations are required, rural bus stops are not necessary. This will be used to provide the nearest transit stations at a particular place (for a buy/sell listing), similar to whwat Yelp did for its listings.
Yelp's Transit Details
Nearest Transit Station: Haymarket Station - Outbound (Orange Line) Haymarket Station - Inbound (Orange Line) Congress St @ Haymarket Sta (191, 192, 193, 325, 326, 4, 92, 93)
Any suggestions? Does OSM have such information? Could OSM contributors have included the major transit locations in America, and is it currently at least comprehensive in the major cities?
And what do I have to do to clean the data before I can import it into PostGIS and QGIS/ArcGIS?