Editing Bay Area Rapid Transit (section)

=== Origins, planning, and geographical coverage ===
Some of the Bay Area Rapid Transit system's current coverage area was once served by an electrified [[Tram|streetcar]] and suburban train system called the [[Key System]]. This early 20th-century system once had regular transbay traffic across the lower deck of the [[San Francisco–Oakland Bay Bridge|Bay Bridge]], but the system was [[General Motors streetcar conspiracy|dismantled]] in the 1950s, with its last transbay crossing in 1958, and was superseded by highway travel. A 1950s study of traffic problems in the Bay Area 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 new, high-speed rapid transit system linking the cities and suburbs.<ref>{{Cite web |title=A History of BART: The Concept is Born |url=https://www.bart.gov/about/history |access-date=October 8, 2019 |publisher=Bay Area Rapid Transit}}</ref> Marvin E. Lewis, a San Francisco trial attorney and member of the city's board of supervisors spearheaded a grassroots movement to advance the idea of an alternative bay crossing and the possibility of regional transit network.<ref>{{Cite book |last=Healy, Michael C. |title=BART: The Dramatic History of the Bay Area Rapid Transit System |publisher= Heyday |year=2016 |isbn=978-1-59714-370-7 |location=Berkeley, California |oclc=948549791}}</ref>

Formal planning for BART began with the setting up in 1957 of the [[Bay Area Rapid Transit District|San Francisco Bay Area Rapid Transit District]], a [[special-purpose district|county-based special-purpose district]] body that governs the BART system. The district initially began with five members, all of which were projected to receive BART lines: [[Alameda County]], [[Contra Costa County, California|Contra Costa County]], [[San Francisco|the City and County of San Francisco]], [[San Mateo County, California|San Mateo County]], and [[Marin County, California|Marin County]]. Although invited to participate, Santa Clara County supervisors elected not to join BART due to their dissatisfaction that the peninsula line only stopped at [[Palo Alto]] initially, and that it interfered with suburban development in [[San Jose, California|San Jose]], preferring instead to concentrate on constructing freeways and expressways. Though the system expanded into Santa Clara County in 2020, as of June 2024 it is still not a district member.

In 1962, San Mateo County supervisors voted to leave BART, saying their voters would be paying taxes to carry mainly Santa Clara County residents (presumably along [[Interstate 280 (California)|I-280]], [[California State Route 92|SR 92]], and [[California State Route 85|SR 85]]).<ref>{{Cite news |date=March 12, 2013 |title=History of BART to the South Bay |work=[[San Jose Mercury News]] |url=http://www.mercurynews.com/bart/ci_5162648 |access-date=October 22, 2013}}</ref> The district-wide tax base was weakened by San Mateo's departure, forcing Marin County to withdraw a month later. Despite the fact that Marin had originally voted in favor of BART participation at the 88% level, its marginal tax base could not adequately absorb its share of BART's projected cost. Another important factor in Marin's withdrawal was an engineering controversy over the feasibility of running trains on the lower deck of the [[Golden Gate Bridge]], an extension forecast as late as three decades after the rest of the BART system.<ref>{{Cite web |title=A History of BART: The Concept is Born |url=http://www.bart.gov/about/history/ |access-date=October 22, 2013 |publisher=Bart.gov}}</ref><ref name="barthistory">{{BART History}}</ref><ref>See BART Composite Report, prepared by Parsons Brinkerhof Tutor Bechtel, 1962</ref> The withdrawals of Marin and San Mateo resulted in a downsizing of the original system plans, which would have had lines as far south as Palo Alto and northward past [[San Rafael, California|San Rafael]]. Voters in the three remaining participating counties approved the truncated system, with termini in [[Fremont, California|Fremont]], Richmond, Concord, and Daly City, in 1962.<ref>{{Cite web |title=A History of BART: the Concept is Born |url=http://www.bart.gov/about/history |access-date=December 1, 2018}}</ref>

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, particularly in Alameda and Contra Costa counties; [[Berkeley Hills Tunnel|tunneling through the Berkeley Hills]] on the Concord line; and lowering the system's centerpiece, the [[Transbay Tube]] connecting Oakland and San Francisco, into a trench dredged onto the floor of San Francisco Bay.<ref>{{Cite web |title=A History of BART: The Project Begins |url=http://www.bart.gov/about/history/history2 |access-date=December 1, 2018 |website=Bay Area Rapid Transit}}</ref> 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.<ref>{{Cite journal |last=W. S. Homburger |title=The impact of a new rapid transit system on traffic on parallel highway facilities |journal=Transportation Planning and Technology |volume=4 |issue=3}}</ref> BART envisioned frequent local service, with [[headway]]s as short as two minutes between trains through the Transbay Tube and six minutes on each individual line.<ref name="US Congress OTA_2">{{Cite web |date=May 1, 1976 |title=Automatic Train Control in Rail Rapid Transit |url=https://www.princeton.edu/~ota/disk3/1976/7614/7614.PDF |access-date=March 15, 2017 |publisher=United States Congress Office of Technology Assessment |page=46 |quote=When BART reaches its full level of service, headways will be reduced to 2 minutes in San Francisco and 6 minutes elsewhere during peak periods...}}</ref>