Forty-six years after transit officials first envisioned building a high-speed rail connection from San Francisco to the city’s airport, their dream became reality. In June 2003, Bay Area Rapid Transit (BART) opened an 8.7-mile extension of its heavy rail system to the San Francisco International Airport. The $1.48 billion project, which took five years to complete, included the construction of an underground subway, aerial bridge structures and transit stations.

When BART was created in 1957, transit officials began planning a high-speed rail network that would connect the geographically diverse region and move passengers through the San Francisco metropolitan area. Steadily, the agency built the transit network components to meet demand for service, opening the first 75-mile leg in 1972.

In 1991, BART was selected by the Federal Transit Administration’s (FTA) Turnkey Demonstration Program to test new procurement contracting practices for major transit projects during the construction of the extension to the airport from an existing BART station at Colma. Plans for the extension included constructing 6.1 miles of subway tunnel and four transit stations. The BART stations would be situated at South San Francisco, San Bruno, and San Francisco International Airport, and an intermodal station at Millbrae would connect BART with the Caltrain commuter rail system that extends 180 miles from San Francisco to San Jose.

The federal program required that BART consolidate several contracts for the extension into a few design/build or design/build/operate contracts. In 1998, three out of four major design-build contracts for the extension were awarded to a team consisting of Sylmar, Calif.-based Tutor-Saliba/Slattery, a general contractor, and Kansas City, Mo.-based HNTB, a design firm. The team received the Line, Trackwork and Systems contract; the San Bruno Station and Parking Structure contract; and the South San Francisco Station and Parking Structure contract.

When the team started design and construction of the subway tunnel, they encountered a unique set of challenges. The tunnel passed through the cities of Colma, South San Francisco, San Bruno and Millbrae and crossed under 20 existing city streets. To keep all local streets open to traffic and to avoid disturbing businesses and residences, the team built temporary bridges for automobiles to travel over the work sites.

During construction of a 1.2-mile aerial guideway from the Millbrae station to the San Francisco International Airport, the team had to develop environmental mitigation plans to preserve sensitive wetlands that served as habitats for endangered species. The team designed and built a temporary work platform upon which all construction activity took place to avoid disturbing the sensitive environment. Additionally, construction workers attended special endangered species and wetlands preservation training, and biological monitors patrolled the construction site to ensure protection of the endangered species and their habitat.

Since the extension’s opening in June, daily ridership has reached 25,000 trips per day, and officials expect ridership to reach 70,000 trips by 2010. More than 100,000 passengers boarded the new extension during its first week in service. “The newly opened extension will eliminate 10,000 daily automobile trips to the airport, significantly contributing to the region’s efforts to relieve traffic congestion and comply with air-quality attainment regulations,” says Mike Callan, a BART project manager for the extension.

The project was funded with $750 million from the FTA, $200 million from the San Francisco International Airport, $183.7 million from BART, $171 million from the San Mateo County Transit District, $152 million from the California Transportation Commission and $26.5 million from the Metropolitan Transportation Commission. The extension brings the total BART system to 104 miles with 43 stations, and its direct connection to the airport provides passengers with a new link to the rest of the world.