San Francisco drivers are in for a rough weekend. Caltrans is shutting down eastbound Interstate 80, the Bayshore Freeway, between 17th and 4th streets from 11 PM April 17 to 6 AM April 20, a roughly 55-hour full closure. During that window, crews will place polyester concrete overlays, repair bridge joints and tackle other deck and structural work designed to extend the viaducts' service life and smooth out the ride.
According to Caltrans District 4, the closure stretches about 1.6 miles and includes the shutdown of the northbound and southbound U.S. 101 connector ramps to eastbound I-80. The agency is warning of heavy congestion throughout SoMa and Mission Bay. The last eastbound exit before the barricades go up will be Vermont Street, and anyone who misses it could find themselves funneled through 9th Street and Bryant to reach the 5th Street on-ramp.
Why crews need the full shutdown
The project is part of the region's Fab-4 rehabilitation push to preserve San Francisco's Central and Bayshore viaducts, a two-year program that began in January, according to local reporting. SFGATE reports that crews will be installing polyester overlays, rebuilding joints and repairing barrier rails, all aimed at extending the structures' lifespan and boosting safety for drivers.
Detours, transit and what to expect
Caltrans District 4 says marked detour routes and how-to videos are posted on the project website to help drivers steer around the shutdown. Portable message boards and traffic control staff will be deployed in advance of the work to guide drivers, though patience will definitely be required. SFMTA plans to station parking control officers along major detour corridors and is urging people to lean on public transit for the weekend instead of driving into the tangle.
Travelers should brace for overnight work lighting and gridlock on local streets near 17th, 9th and 10th, 5th and 4th streets as traffic diverts off the freeway and onto city roads not built for that kind of volume.
Who will be hit hardest
The closure is expected to sting most for commuters heading to the Bay Bridge from the peninsula, along with drivers bound for SoMa and Mission Bay hot spots like the Chase Center and Moscone Center. Long delays and creative rerouting are likely to be part of the weekend plan for anyone who insists on driving. NBC Bay Area first published the detailed timeline and detour maps for the shutdown.
For live traffic conditions, check 511.org along with SFMTA advisories before heading out, and review the project's detour maps as the closure weekend approaches. If driving is unavoidable, plan to leave early, stick to posted signs and factor in extra travel time, since delays are likely across the major arterials feeding into the closure zone for the entire weekend.
