Caltrans has begun rehabilitation work on the Central (U.S. 101) and Bayshore (Interstate 80) viaducts in San Francisco as part of the San Francisco Fab-4 Rehabilitation program.
The two-year project focuses on structural repairs to the 71-year-old viaducts near the San Francisco–Oakland Bay Bridge corridor. Work includes placing polyester concrete deck overlays, repairing bridge deck joints, rehabilitating barrier rails, and completing additional deck and structural repairs. Crews began the project with inspections and preparation activities ahead of construction.
The viaducts carry thousands of vehicles daily and form part of one of San Francisco’s most heavily traveled freeway segments. Caltrans initiated the rehabilitation to address age-related wear from traffic loads, weather exposure, and seismic demands, and to extend the service life of the structures.
Construction activity will involve lane reductions, overnight work, and intermittent full closures over the project duration. Caltrans expects work to continue through approximately early 2028.The rehabilitation will preserve the existing viaducts, improve ride quality, and enhance safety for motorists, pedestrians, and cyclists traveling through and beneath the freeway structures.