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PB, in joint venture, completed a 14-kilometer (8.7 mile) extension of the BART system. |
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The BART extension had a minimal impact on the surrounding environment, home to endangered species. |
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Along with the airport connection, the BART extension includes four new stations. |
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Overcoming Diverse Challenges
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Among the challenges faced in the BART extension were vital structural, infrastructure and environmental concerns, all of which were successfully addressed by BATC.
The extension runs adjacent to or under existing heavily developed streets, infrastructure and utilities. More than 350 utilities were rerouted, encased, supported in place or removed. Special care, such as special shoring systems, was used for construction near an active railroad. Several major airport expansion projects also had to be coordinated with the BART expansion.
Seismic activity was an extra consideration, as the extension is situated just over 3 kilometers (2 miles) from the San Andreas Fault. Studies such as soil-structure interaction analyses were conducted and used extensively in the design and construction of the extension.
Aerial structures connecting the transit line with the airport had to be built over wetlands that are home to the endangered San Francisco garter snake and the threatened California red-legged frog. Engineers protected the habitat of these animals by designing wooden trestles for supporting construction equipment, so that impact on the ground was minimized. Reducing noise and vibration in residential areas around a group of cemeteries was accomplished through innovative design and construction techniques.
Pete Snyder, president of the BART board of directors, said, "I marvel at how you put up a major public works project of this magnitude with all its political and environmental nuances...PB and the entire consultant team are to be commended."
According to BART, nearly 49,000 people took BART to the airport during Christmas week 2004. San Mateo County has predicted that the extension's ridership will near 70,000 by 2010, eliminating an estimated 10,000 automobile trips to the airport per day.
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