The Caltrain downtown SF extension would close the gap in the Bay Area's transit systems. Caltrain connects San Francisco to the Peninsula, Silicon Valley and San Jose.|
It currently ends 1 1/2 miles from downtown, so it doesn't connect directly to regional transit systems and most Muni lines. This discourages ridership.
This map depicts the gap that would be closed by the Caltrain extension, and the route of the extension from Caltrain's present terminus at Fourth and Townsend to the Transbay Terminal at First and Mission Streets.