Silicon Valley BART extension

Funding

Santa Clara County was originally going to have been part of the BART system, but local governments did not approve. Minor service at Palo Alto right over the border from San Mateo County was also planned originally.

In 2000, Santa Clara County voters approved a 30-year half-cent sales tax increase to fund BART, which took effect in 2006. To make up for a shortfall in projected federal funding, an increase in the sales tax by ⅛ of 1% was proposed if additional federal funding were secured.

The economy worsened in 2009, and the 2000 sales tax was projected to generate $7 billion which was short of the originally expected $11 billion. As a consequence, the number of planned stations was reduced. In addition, the line from Berryessa to downtown San Jose was delayed until 2025. This line may or may not include Santa Clara.

Construction of the Warm Springs extension began in 2009.

VTA awarded $770 million to Skanska-Shimmick-Herzog in 2011 for the first phase of the Berryessa extension, and the federal government granted $900 million for the project in 2012. Construction began the same year. It was scheduled to open in 2016. Despite substantial incentives if the opening were pulled in by 18 months (from an earlier schedule) to 2016, the Milpitas and Berryessa stations are expected to open in fall 2017 or 2018.

VTA sought funding from the federal New Starts program in 2016. A half-cent 30-year sales tax passed in the 2016 elections, to raise $6.0 to $6.5 billion with up to 25% of this for BART or up to $1.6 billion. VTA also sought $1.5 billion from New Starts, and $750 million from the California Cap and Trade program.

Warm Springs Extension

The $900 million extension to Warm Springs is five miles long, the first part of BART's Silicon Valley extension.

The station is scheduled to open on March 25, 2017. The extension broke ground in 2009. Construction of the station began in 2011, and was expected to take three and a half years. However, the opening was pushed back from the originally projected date of 2014, to fall 2015, to early 2016, to spring 2016, to summer 2016, to fall 2016, to late fall 2016, to winter 2017, and to spring 2017.

Berryessa Extension

Construction of the $2.3 billion Berryessa extension started in 2012, originally scheduled for completion in 2016. While the opening has been delayed to fall 2017, or 2018, transit officials claimed that the project was "ahead of schedule" as of 2016.

The line extends south from Warm Springs to Milpitas station (originally to be called "Montague Station"), connected by pedestrian bridge to the VTA's Montague light rail station near the Great Mall of the Bay Area, and then on to Berryessa station. A proposed infill station in downtown Milpitas, Calaveras station, has been deferred until the city secures funding.

In 2009, VTA proposed to extend the line as far as they could afford (Berryessa) until further funding could be obtained. In 2009, the MTC also changed its rules allowing bridge and HOT lanes tolls to be used for transit projects, such as BART expansion, VTA light rail extensions, bus or ferry operations.

A local industrial park sued in 2011 (without success) on environmental grounds claiming that the extension would reduce vehicular access.

Proposed San Jose/Santa Clara extension

A $4.7-billion final leg is proposed to downtown San Jose, first to the proposed Alum Rock station on the city's "east side", connected by a tunnel under Santa Clara Street to a proposed Downtown San Jose Station, which would be an interchange station to VTA lines. Like the Berryessa Extension, it would be built by VTA, but operated by BART. The original proposal had separate Civic Plaza/SJSU and Plaza de César Chávez stations, but these were consolidated into a single station to cut cost. The line would continue to the San Jose Diridon station (transfer point to Amtrak, Caltrain, Altamont Corridor Express and the planned California High Speed Rail system), and the proposed BART subway station would be called "Diridon/Arena" (SAP Center). It would either terminate there, allowing for a future extension to the proposed Santa Clara Caltrain Station, or go all the way to that station in the same phase of construction. Project details are expected to be finalized by the fourth quarter of 2016.

Originally the entire extension was proposed as one megaproject, but lower than expected federal funding and sales tax revenue reduced the scope of the project. It was divided into phases. After funding was secured for the first phase in March 2012, VTA began looking for $2.4 billion to close the remaining funding gap for the projected $4.7 billion cost of the second phase of the proposed extension to downtown San Jose and Santa Clara. While some sources target completion in 2025, others target mid 2026.