What does the acronym BART stand for in the San Francisco Bay Area rail system?

BART stands for Bay Area Rapid Transit.

The name identifies the San Francisco Bay Area’s regional rapid-transit system, which links San Francisco with communities on both sides of the bay and beyond. BART is operated by the San Francisco Bay Area Rapid Transit District, a special-purpose public agency created to plan and run the network.

The system was conceived during the 1950s, when postwar population growth and increasing automobile traffic created pressure for a faster regional transport alternative. Planning formally took shape with the formation of the district in 1957, and construction began in 1964. The first BART service opened in 1972.

A key engineering feature is the Transbay Tube, which carries trains beneath San Francisco Bay between San Francisco and Oakland. BART is sometimes confused with the Bay Area’s other rail services, such as Caltrain, Muni Metro and Amtrak’s Capitol Corridor, but those are separate systems. The word “Rapid” describes BART’s high-speed, grade-separated regional service rather than a conventional streetcar network.