BART system underground construction works in San Francisco, CA, US

Sandhogs working underground during BART system construction in San Francisco, CA, US, 1969. A film made as a progress report from the Bay Area Rapid Transit (BART) system to the public, showing construction of elevated and subway lines and the changes in the San Francisco Bay Area's regional systems as a result of BART. Construction of the system began in 1964, and included a number of major engineering challenges, including excavating subway tunnels in San Francisco, Oakland, and Berkeley; constructing aerial structures throughout the Bay Area. Like other transit systems of the same era, BART endeavored to connect outlying suburbs with job centers in Oakland and San Francisco by building lines that paralleled established commuting routes of the region's freeway system.