All northbound lanes of US-101 through San Francisco will close Friday, Sept. 18 through Monday, Sept. 21 for major pavement work at Hospital Curve.
Caltrans announced the full closure between Cesar Chavez Street and 17th Street, starting at 11 p.m. Friday and lasting until 6 a.m. Monday. All southbound lanes will stay open.
The shutdown is the second of four planned weekend closures for the Fab 4 Hospital Curve Rehabilitation Project, a pavement overhaul that began in fall 2025. Crews will work around the clock to replace concrete pavement panels, according to the agency.
What San Rafael drivers need to know
Caltrans is directing northbound travelers to use I-280 as the primary detour toward downtown San Francisco and the Bay Bridge. The agency said public transportation is the best option to avoid delays.
A second detour runs southbound on I-280 to the 19th Avenue or Monterey Boulevard off-ramps, then onto San Jose Avenue and Guerrero Street. Caltrans has also prepared a dedicated detour map for travelers heading to or from San Francisco International Airport and the SFO Rental Car Center.
The first Hospital Curve closure took place over Labor Day weekend, Sept. 4–7. Two more are scheduled, both affecting southbound lanes:
- Friday, Oct. 2 at 11 p.m. through Monday, Oct. 5 at 6 a.m.
- Friday, Oct. 16 at 11 p.m. through Monday, Oct. 19 at 6 a.m.
All work is weather dependent.
Motorists can check real-time conditions at 511.org or Caltrans QuickMap at quickmap.dot.ca.gov. 511 SF Bay posted a reminder about the Sept. 18–21 closure on Monday, Sept. 14.
