About the bridge

The San Francisco-Oakland Bay Bridge is the region's workhorse bridge, carrying more than a third of the traffic of all of the state-owned bridges combined.

It is made up of two bridge segments: a cantilever portion between Oakland and Yerba Buena Island, and a suspension span from the island to San Francisco. Connecting the two is the largest diameter bore tunnel in the world.

Seismic retrofit of the western span of the bridge was completed in 2004. The eastern span, damaged in the 1989 Loma Prieta earthquake and subsequently repaired, will be replaced rather than simply strengthened.