Seismic safety retrofit work on the approach to the west span of the San Francisco/Oakland Bay Bridge from downtown San Francisco involved completely removing and replacing this one-mile multi-level stretch of Interstate 80 and six on- and off-ramps in its original footprint. This work occurred while more than 280,000 vehicles flowed daily in the midst of this essential construction.

To minimize disruptions to the neighborhood and to keep the bridge’s traffic moving, the project was performed in a series of six elaborate stages, including a series of lane shifts, regular lane and ramp closures, and one partial bridge closure. Each of the six stages of retrofit work followed a carefully staged formula to meet seismic safety standards. A temporary structure was built and vehicles were rerouted to it. The old structure was then demolished and work began on the new structure in the original footprint. Drivers were then rerouted back onto the completed replacement structure, and the temporary structure was demolished.