We with [Komяpa] made own public transport overlay. Features: whole world coverage, daily updates and some preprocessing to make things neater. Currently, overlay renders bus, trolleybus and tram routes and stops. Check it: over osm mapnik layer: http://latlon.org/pt?zoom=10&lat=55.73677&lon=37.62758&layers=B0T and google satellite and mapsurfer osm street names: http://latlon.org/maxi?zoom=14&lat=55.65723&lon=37.48861&layers=B0000000000