Bay Area Rapid Transit

Bay Area Rapid Transit (BART) is a public transportation system serving the San Francisco Bay Area. The rapid transit elevated and subway system connects San Francisco with cities in Alameda, Contra Costa, and San Mateo counties. BART operates 5 routes on 104 miles (167 km) of track connecting 44 stations, plus a 3.2-mile (5.1 km) automated guideway transit line to the Oakland International Airport which adds a 45th station. A spur line in eastern Contra Costa County will utilize other rail technologies. With an average of 420,000 weekday passengers and 126 million annual passengers in fiscal year 2015,[1] BART is the fifth-busiest heavy rail rapid transit system in the United States. The system's acronym is pronounced "Bart," like the name, and not as a spelled-out initialism (i.e., "B-A-R-T").

BART is operated by the San Francisco Bay Area Rapid Transit District, formed in 1957. As of 2017, it is being expanded to San Jose with the consecutive Warm Springs and Silicon Valley BART extensions.