VTA has two important responsibilities: 1) Development, operation and maintenance of the bus and light rail system within the county. 2) Management of the county's blueprint to reduce congestion and improve air quality.

Caltrain runs between San Francisco and San Jose, with weekday commute-hour service to Gilroy. Key destinations along the Caltrain line include Pacific Bell Park, Stanford University, The Compaq Center and the San Francisco and San Jose international airports.

The Altamont Commuter Express (ACE Rail) is a commuter train that runs between Stockton and San Jose California.