Corridor Overview
The seismic retrofit of the San Francisco-Oakland Bay Bridge is more than an upgrade to one of the country’s busiest bridges; it is an epic transformation into a global icon, featuring some of the most cutting-edge and innovative engineering, construction and seismic technology.
The path forward has not always been an easy one. Public safety is of the utmost importance and prime motivation in building the new Bay Bridge. We have not forgotten the lessons learned from the Loma Prieta earthquake, or that the clock is always ticking.
When a 250-ton section of the East Span’s upper deck collapsed during the 7.1-magnitude earthquake, it was a wake-up call for the entire Bay Area. While the East Span quickly reopened after a month of repairs, critical questions lingered: how could the Bay Bridge—an important regional lifeline structure— be strengthened to withstand the next major earthquake? Should the bridge be repaired or rebuilt? These were among the essential decisions to be made to ensure that the Bay Bridge would survive heavy seismic activity and provide access for emergency services and rebuilding efforts following a major earthquake.
The California Department of Transportation determined that the only way to achieve these goals was to build a new bridge. The region, working through the Metropolitan Transportation Commission with the assistance of the Department, developed the current design concept for construction of this iconic structure.
- Connects San Francisco with the East Bay
- Opened November 12, 1936
- Comprised of two separate bridges, a tunnel, and a mile long elevated roadway
- Total project length (bridge and approaches): 8.4 miles (from the MacArthur Maze freeway interchange in Oakland to the end of the 5th Street off-ramps in San Francisco)
- Daily average number of vehicles that use the Bay Bridge: 280,000
- Daily average number of vehicles that use the Golden Gate Bridge: 100,000
- East Span damaged in 1989 Loma Prieta earthquake







