Warm Springs Extension Project History & Chronology

When the extension was originally proposed in 1991, congestion on I-880, the major regional travel corridor linking Santa Clara, Alameda and Contra Costa counties, was already severe. Since then, traffic congestion has escalated and its volume has become unacceptable.

Transportation is critical for people living and working in the southern Alameda County and northern Santa Clara County portions of the San Francisco Bay Area. In 2000, it was estimated that there were approximately 400,000 weekday automobile trips between the East Bay and Santa Clara County. By 2025, this number is expected to exceed 500,000 vehicle trips (MTC). The purpose of the Warm Springs Extension is to reduce overall traffic congestion and improve the regional transit network by shortening the travel distance for connecting transit services to and from points to the south. The extension will also reduce transit travel times and improve reliability. In addition, the extension will bring other benefits to the surrounding communities through BART's commitment to environmental quality and land use.

Environmental Quality: As patrons transfer from auto travel to transit travel, there is a corresponding reduction in the number of automobile miles traveled, resulting in conservation of non-renewable energy. The extension will promote reduction of air-polluting auto trips and support regional plans to meet state and federal air quality standards.

Land Use: The extension responds to BART's System Expansion Criteria by demonstrating a commitment to transit-supportive growth and development, which is designed to maximize ridership by supporting smart, efficient, and desirable growth patterns. The City of Fremont is the lead agency for developing the City's future land use and redevelopment goals around the Warm Springs / South Fremont Station. BART will continue to support the City in its efforts to encourage transit-oriented development around both the Warm Springs / South Fremont and Irvington Stations.

Ridership: The Warm Springs Extension will result in an increase in transit trips, particularly those destined for, originating in, or passing through southern Alameda County. The extension will increase transit ridership by 4,700 daily trips upon opening and 7,200 daily trips by 2025. The Irvington Station would provide an increase of 5,700 and 9,100 daily trips by 2025. This increase in transit trips indicates a shift in use from automobiles to transit.



BART prepared an Environmental Impact Report (EIR) for the Warm Springs Extension project (WSX) that analyzed a series of alternatives for extending the BART system to the Warm Springs District of Fremont.


BART's Board of Directors certified the Final EIR and adopted a project for the WSX; however, the project was not constructed because sufficient funds were not available. Public support has remained strong for the extension of rail transit service from Fremont to southern Alameda County. In response to public interest, BART and other transit agencies continued to study both the project adopted in 1992 and larger regional corridor projects.


The Metropolitan Transportation Commission (MTC) prepared the Fremont-South Bay Corridor Report, which analyzed several alternatives for transit service in the regional corridor, including a BART alignment.


BART and the Santa Clara Valley Transportation Authority (VTA) collaborated to prepare the BART Extension Study from Fremont to Milpitas, San Jose and Santa Clara, which examined a BART alignment along the Union Pacific (UP) railroad right-of-way. That same year, Alameda County voters reauthorized Alameda County's transportation sales tax (Measure B) to provide funding for a series of transportation-related projects, including a BART extension from Fremont to Warm Springs.


VTA purchased the former Western Pacific (WP) Milpitas Line from UP, which extends approximately 15 miles from Fremont to San Jose. Read more on BART to Milpitas/San Jose/Santa Clara.


The state environmental review process was concluded according to the requirements of the California Environmental Quality Act (CEQA). On March 25, 2003 the Draft Supplemental Environmental Impact Report (Draft SEIR) was circulated for public review. On June 26, 2003 the BART Board of Directors certified that theFinal SEIR was complete and in compliance with CEQA requirements and adopted the project. On October 9, 2003 the BART Board of Directors approved WSX for construction as a Design-Build "Best Value" project. View the Executive Summary (1.27 mb) of the SEIR.


The Warm Springs Extension was originally approved by BART as a state and locally funded project. Changes in state transportation priorities resulted in BART seeking to become eligible for federal funds. To become eligible for such funds, the project was required to complete an environmental review under the National Environmental Policy Act (NEPA).


In March of 2005, the Draft Environmental Impact Statement (DEIS) for the Warm Springs Extension Project was published under the National Environmental Policy Act (NEPA).


The Federal Transit Administration (FTA), as lead federal agency, and BART released a Final Environmental Impact Statement (FEIS) for the Warm Springs Extension Project in July of 2006. The FTA and BART considered and incorporated the results of previous studies into the FEIS, including the 1992 BART Warm Springs Extension Environmental Impact Report (EIR) and the 2003 Supplemental EIR. In addition, the FEIS complies with other environmental requirements that apply only to federal actions and not to the CEQA analysis previously conducted. These requirements include:

  • Executive Orders on Environmental Stewardship, Transportation Infrastructure, Environmental Justice, Floodplain Management, and Protection of Wetlands

  • Federal Department of Transportation Act (Section 4(f))

  • Federal Land and Water Conservation Fund (Section 6(f))

  • National Historic Preservation Act (Section 106)

The Final SEIR and the FEIS are available at the Fremont Main Library and the MTC/ABAG library. These documents are also available for public review at the BART Transit System Development Office, 300 Lakeside Drive, 21st Floor, Oakland, CA 94612. You may also download a copy of the Executive Summary of the DEIS or view the two-volume FEIS.

The FTA issued a Record of Decision (ROD) on October 24, 2006, which determined that the NEPA requirements have been satisfied for the Warm Springs Extension project. You may download a copy of the ROD, the Mitigation Monitoring and Reporting Plan (MMRP) or the Memorandum of Agreement (MOA) relating to cultural resources.

In 2006, the Alameda County Transportation Improvement Authority (ACTIA) created a Policy Advisory Committee (PAC) to address project funding and implementation challenges facing the project. The WSX PAC is composed of representatives from ACTIA, the Metropolitan Transportation Commission (MTC), the Alameda County Congestion Management Agency (ACCMA), the Santa Clara Valley Transportation Authority (SCVTA), the City of Fremont, and BART.


Following receipt of the ROD in late 2006, BART re-evaluated its implementation strategy for the project and began preparing for the final design and construction phases. First, an agreement was reached with the City of Fremont for the construction of the BART Paseo Padre Parkway Overpass structure as part of the City's Washington Blvd/Paseo Padre Parkway Grade Separation Project. Constructing the BART structure as part of the City's contract would eliminate the need for costly and disruptive demolition and reconstruction later on. The Grade Separation contract was awarded and construction began in the Spring of 2007.

Secondly, Right-of-Way acquisition activities for the WSX project resumed in earnest, including the purchase of approximately 3.5 miles of the former WP ROW from VTA in the summer of 2007.

Third, BART began final design of the subway beneath Fremont Central Park as a stand-alone contract package (Subway). This approach is intended to minimize overall escalation costs and deal with the special needs associated with the underground portion of the project.

Fourth, technical studies resumed in the area of systems engineering in preparation for the Line, Track, Station & Systems (LTSS) contract, which would complete the design and construction of the extension.


Final Design for the Subway contract was completed and preparation began to advertise the contract in early 2009. For the LTSS contract preliminary design, particularly in the area of systems engineering, continued through the year.

Construction of the BART overpass structure at Paseo Padre Parkway was completed in the summer, as part of the City of Fremont’s Washington Boulevard/Paseo Padre Parkway (Railroad) Grade Separation project.

BART’s Real Estate team continued Right of Way acquisition efforts throughout the year.

BART began work with the City of Fremont to study constructability of the future Irvington Station.


Construction Notice to Proceed (NTP) given on August 24th for the Fremont Central Park Subway contract.

Ground breaking ceremony held September 30, 2009.


The City of Fremont's Grade Separation project was completed and opened to the public.

As part of the WSX Subway Contract, the new dog park, basketball courts and parking facilities were completed; work began on the subway excavation support system.

The north eastern lobe of Lake Elizabeth was dewatered and a cofferdam installed.

The RFQ and RFP were released for the LTSS contract.


The BART Board authorized award of the Tail Track Building Demolition contact to Aztec Consultants on June 9, 2011.

The BART Board authorized award of the Design-Build Line, Track, Station and Systems (LTSS) contract to Warm Springs Constructors on June 23, 2011.


Line, Track, Station and Systems (LTSS) construction continues.


Line, Track, Station and Systems (LTSS) testing began in Spring 2015.

Tracks and other BART facilities (i.e., substations) along the new alignment energized (powered on) November 2, 2015.

Power Train testing began with first train (non-service for testing only) on track starting December 9, 2015.

"Dynamic" Train Testing, testing of "non-service" BART trains on the new 5.4-miles of track extending south from BART Fremont Station to the new Warm Springs/South Fremont Station commenced on December 14, 2015.


The project entered the final stages of physical construction work, including site paving, landscaping and irrigation work. Systems testing began at an intensely focused pace.


The Warm Springs / South Fremont Station opened for passenger service on March 25, 2017.


Updated July 2019