Silicon Valley BART extension

The Silicon Valley BART extension is an ongoing effort to expand the Green and Orange Line service by Bay Area Rapid Transit (BART) into Santa Clara County via the East Bay from its former terminus at the Fremont station in Alameda County. Planned since at least 1981, the project has seven stations in three sequential phases.

The first phase, known as the Warm Springs Extension, was built by BART at a cost of $790 million, terminating at the new Warm Springs/South Fremont station. Construction began in 2009, and the extension and new station opened in 2017.

The $2.3-billion second phase, known as BART Silicon Valley Phase I or the Berryessa Extension, includes two new stations, Milpitas and Berryessa/North San José. Construction began in 2012, and the extension and its two new stations were inaugurated on June 12, 2020, while service for the public began on the next day. Many credited the former Mayor of San Jose, Ron Gonzales, with bringing this project to fruition.

The $12.2-billion third phase to downtown San Jose, known as BART Silicon Valley Phase II, remains unfunded. Targeted for completion in 2036, it would add three new subway stations south of Berryessa: 28th Street/Little Portugal, Downtown San José, Diridon, and a surface station in Santa Clara. Initial testing and preliminary construction activities began in January 2019.

The Santa Clara Valley Transportation Authority (VTA) built the Berryessa Extension and intends to build the final downtown San Jose extension, but BART operates and maintains the completed portion of the extension and will also do so for the final phase when completed.