History of Bay Area Rapid Transit  Bay Area Rapid Transit, widely known by the acronym BART, is the main rail transportation system for the San Francisco Bay Area. It was envisioned as early as 1946 but the construction of the original system began in the 1960s. The idea of an underwater electric rail tube was first proposed in the early 1900s by Francis "Borax" Smith – the "San Francisco Chronicle" ran a front-page editorial in 1900 suggesting an electrified subway. There were also plans for a third-rail powered subway line ("Twin Peaks Tunnel") under Market Street in the 1910s. A 1915 study prepared for the cities of Oakland and Berkeley called a rapid transit link between the two cities "imperative," suggesting new street railway lines or an elevated railway between the two cities. Much of BART's current coverage area was once served by the electrified streetcar and interurban train network called the Key System. This early twentieth century system once had regular transbay traffic across the lower deck of the San Francisco–Oakland Bay Bridge. The final passenger run occurred on April 20, 1958 and the entire system was soon dismantled in favor of automobiles and buses and the explosive growth of highway construction. Proposals for the modern rapid transit system now in service began in 1946 by Bay Area business leaders concerned with increased post-war migration and growing congestion in the region. An Army-Navy task force concluded that an additional trans-bay crossing would soon be needed and recommended a tunnel; however, actual planning for a rapid transit system did not begin until the 1950s. In 1951, California's legislature created the San Francisco Bay Area Rapid Transit Commission to study the Bay Area's long-term transportation needs. The commission's 1957 final report concluded the most cost-effective solution for the Bay Area's traffic woes would be to form a transit district charged with the construction and operation of a high-speed rapid rail system linking the cities and suburbs. Nine Bay Area counties were included in the initial planning commission. The San Francisco Bay Area Rapid Transit District was formed by the state legislature in 1957, comprising the counties of Alameda, Contra Costa, Marin, San Francisco, and San Mateo. Because Santa Clara County opted instead to first concentrate on its Expressway System, that county was not included in the original BART District. In 1959 a bill was passed in the state legislature that provided for the entire cost of construction of the tube to be paid for with surplus toll revenues from the San Francisco–Oakland Bay Bridge. This represented a significant portion of the total cost of the system.