Calaveras station

VTA's BART Silicon Valley Extension Program

Company type	Public transit project
Industry	Public transportation
Founded	1981
Headquarters	Santa Clara , United States
Area served	Santa Clara County, California, United States
Key people	Ron Gonzales (former San Jose Mayor, notable supporter)
Products	Bay Area Rapid Transit extension service
Owner	Santa Clara Valley Transportation Authority (VTA)

The Silicon Valley BART extension—officially named VTA's BART Silicon Valley Extension Program and commonly referred to as BART Silicon Valley—represents a continuing effort to extend Bay Area Rapid Transit (BART) service into Santa Clara County, beginning from its previous endpoint at Fremont station in Alameda County. This initiative, which has been planned since at least 1981, involves the development of seven stations spread over three distinct phases.

The initial phase, known as the Warm Springs Extension, involved an investment of $790 million and introduced the Warm Springs/South Fremont station. Construction commenced in 2009, with passenger service launching in 2017.

The second phase, called BART Silicon Valley Phase I or the Berryessa Extension, carried a budget of $2.3 billion and added two stations: Milpitas and Berryessa/North San José. Construction began in 2012, and the extension was opened to the public in June 2020. This phase was notably advanced through efforts by former San Jose Mayor Ron Gonzales.

Phase three, labeled BART Silicon Valley Phase II, aims to extend service into downtown San Jose but remains without secured funding and is projected for completion by 2036. This stage will introduce three underground stations—28th Street/Little Portugal, Downtown San José, and Diridon—as well as a surface-level station at the Santa Clara Transit Center. Initial construction activities started in January 2019.

The Santa Clara Valley Transportation Authority (VTA) was responsible for constructing the Berryessa Extension and is slated to oversee the final downtown segment's construction. Meanwhile, BART operates and maintains the existing sections and will continue to do so for future extensions.

Funding

Although Santa Clara County was originally included in BART system plans, local authorities did not grant approval. Early proposals also envisioned limited service near Palo Alto and San Mateo County.

In 2000, voters in Santa Clara County passed a half-cent sales tax increase set for 30 years to finance BART expansion, effective from April 2006. To mitigate a shortfall in anticipated federal contributions, an additional quarter-percent sales tax hike was proposed contingent on receiving federal funds. However, in 2004, the Federal Transit Administration (FTA) issued a "Not Recommended" rating due to concerns about VTA’s capacity to manage both BART and bus operations simultaneously. Despite this setback, VTA proceeded with design and environmental assessments.

By 2006, the Santa Clara County Board of Supervisors proposed another half-cent sales tax increase aimed at transportation and county services; this measure received backing from proponents of the BART extension and labor organizations but was ultimately rejected by voters with a 58% to 42% margin. Later that year, VTA allocated $135 million for engineering and environmental clearances related to the extension and planned to propose a tax increase in 2008 to cover operating expenses.

In November 2008, Measure B was approved by voters—a 30-year local sales tax of one-eighth cent dedicated specifically to funding operating and maintenance expenses for the BART Silicon Valley extension. This tax took effect in July 2012.

The economic downturn of 2009 caused projected revenues to decline from $11 billion to $7 billion, resulting in a reduction of planned stations and postponing the Berryessa-to-downtown San Jose segment’s completion until 2026.

In 2011, VTA awarded a $770 million contract to Skanska-Shimmick-Herzog for constructing Phase I of the Berryessa Extension (Milpitas and Berryessa/North San Jose stations), followed by $900 million in federal grants approved in 2012. Construction began that same year with an anticipated opening originally set for 2016.

For Phase II funding efforts, VTA applied for federal New Starts funds in 2016. That year also saw voter approval of a half-cent sales tax lasting 30 years expected to generate between $6.0 billion and $6.5 billion; up to $1.6 billion of this amount was earmarked for BART projects. Additional funding pursuits included requests for $1.5 billion from New Starts and $750 million from California’s Cap and Trade program.

In 2018, VTA secured $2.6 billion through California’s Transit and Intercity Rail Capital Program financed by the gas tax legislation passed in 2017. By August 2019, it obtained an additional $125 million from the FTA under an accelerated funding initiative.

Although $140 million was initially included in the House version of the American Rescue Plan Act of 2021, this allocation was later removed during Senate negotiations.

In August 2024, the FTA pledged $5 billion towards Phase II funding. Following resolution of current financing gaps, VTA intends to submit an application for a Full Funding Grant Agreement.

Phases

The project is organized into three distinct stages.

Phase	Designation	Duration	Stations	Groundbreaking	Launch	Expense ($ billions)
1	Warm Springs (WSX)	5.4 mi (8.7 km)	Template:Bart	REDIRECT Template:Date table sorting || rowspan=2 | REDIRECT Template:Date table sorting || rowspan=2 |0.79
			Template:Bart
2	Berryessa (SVX Phase 1)	10 mi (16 km)	Template:Bart	REDIRECT Template:Date table sorting || rowspan=3 | REDIRECT Template:Date table sorting || rowspan=3 |2.3
			Template:Bart
			Template:Bart
3	Downtown San Jose/ Santa Clara (SVX Phase 2)	6 mi (9.7 km)	Template:Stn	Jun 14, 2024	2036 (planned)	12.2
			Template:Bart
			Template:Bart
			Template:Bart

Warm Springs extension

The 5.4-mile stretch extending from Fremont station to Warm Springs/South Fremont commenced revenue operations in March 2017. Initially projected at $890 million, the final expenditure was lowered to $790 million after reducing the cost of the subway segment beneath Lake Elizabeth from $249 million to $136 million.

Construction kicked off in 2009, but the station's opening was postponed from the original 2014 completion date to spring 2017 due to software complications and other challenges. Work on the Warm Springs/South Fremont station began in 2011 and was anticipated to take roughly three and a half years.

Serving as the northern endpoint of the Berryessa Extension, the Warm Springs/South Fremont station marks the transition point for the line continuing southward.

Berryessa extension

The Berryessa extension adds roughly 10 miles of track reaching north San Jose with stations at Milpitas and Berryessa. An infill station proposed for Calaveras Boulevard in downtown Milpitas has been postponed pending municipal funding. The Milpitas Station is linked by a pedestrian bridge to VTA’s Milpitas light rail stop near the Great Mall of the Bay Area.

Originally conceived as a single Silicon Valley Extension project spanning from Fremont to Santa Clara, funding limitations necessitated its division into two phases: Phase 1 terminating at Berryessa and Phase 2 continuing through downtown San Jose to Santa Clara. The scope of Phase 1 was constrained by VTA light rail’s budgetary restrictions. In 2011, a local industrial park filed an unsuccessful environmental lawsuit opposing the project due to concerns over diminished vehicle access.

The extension faced several delays, pushing its completion well past the initial target year of 2016. Ultimately, after multiple postponements, both Milpitas and Berryessa stations were inaugurated on June 13, 2020, representing a major expansion of BART service into Santa Clara County.

Downtown San Jose/Santa Clara extension

The concluding segment of the Downtown San Jose/Santa Clara extension, with an estimated cost of $6.8 billion, predominantly features an underground tunnel. This section stretches southward from Berryessa, passing beneath the Bayshore Freeway to reach the 28th Street/Little Portugal station located on the eastern side of San Jose. From there, the tunnel proceeds westward beneath Santa Clara Street to arrive at a Downtown San Jose subway station, which will provide a connection to the VTA light rail at Santa Clara. Initially, plans included separate stations at Civic Plaza/SJSU and Plaza de César Chávez; however, these were merged into a single station to lower expenses. The route continues underground to San Jose Diridon station, a key interchange serving Amtrak, Caltrain, Altamont Corridor Express, VTA light rail, bus lines, and the future California High-Speed Rail. The BART stop at this location will be designated "Diridon." Beyond this point, the extension emerges above ground near the existing Santa Clara Caltrain Station. Additionally, a BART maintenance facility will be constructed at Newhall on property acquired by VTA from Union Pacific. Similar to the Berryessa Extension, VTA is responsible for construction while BART will manage operations.

Following the funding approval for Berryessa in March 2012, VTA pursued additional financing for this $6.8 billion phase.

In late 2017, a disagreement arose between VTA and BART regarding tunnel design: VTA advocated for a single large-diameter bore with vertically stacked tracks to reduce construction time and avoid disruptive cut-and-cover methods along Santa Clara Street; city representatives opposed cut-and-cover due to previous disturbances. Conversely, BART preferred dual smaller bores to maintain cost efficiency and adhere to standardized emergency protocols. Throughout 2018, local businesses and municipalities supported the single-bore option. The decision was deferred for three months; by March 2018, both agencies reached consensus on implementing the single-bore design. Subsequently, a $125 million engineering contract for this tunnel approach was awarded to a collaboration between London-based Mott MacDonald and San Francisco-based PGH Wong Engineering.

Work on construction and soil testing commenced in January 2019. By September of that year, project timelines were extended by three to four years, shifting anticipated revenue service to 2029–2030. On October 15, 2021, VTA revealed intentions to finalize station construction contracts by summer 2022. In May 2022, Kiewit Shea Traylor Joint Venture (KSTJV) secured the primary contract responsible for boring the four-mile tunnel from Berryessa to Diridon and constructing the one-mile above-ground track segment from Diridon to Santa Clara. However, in October 2023, completion estimates were pushed back further to 2036. By June 2025, VTA staff recommended terminating the KSTJV agreement due to unresolved cost issues, which could result in an additional delay of approximately 18 months.

See also

• Bay Area Rapid Transit expansion
• List of Bay Area Rapid Transit stations

External links

• VTA BART Silicon Valley Phase II Extension Project
• VTA's BART Silicon Valley Extension Program
• San Jose Mercury News: BART news section
• MTC.gov report on extension