Seismic safety retrofit work on the West Approach — bordered by 5th Street and the Anchorage at Beale Street — involved completely removing and replacing this one-mile 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.
The West Approach originally had one foundation system supporting both an upper and lower deck configuration from 3rd Street to Beale Street. Each deck now has its own independent column and foundation support system, a crucial aspect of making the West Approach seismically sound. The roadways between 3rd and 5th Streets are parallel concrete decks that transition into the double-deck configuration as drivers approach the West Span of the Bay Bridge.
Work on the 72-year-old structure began in 2003 and was completed in early 2009. To keep traffic flowing, and to enable work to occur in the densely populated residential and commercial hub south of Market Street, builders performed a ”retrofit by replacement,” one of the most complex projects in Caltrans history.