Just in time for students to return to school, the San Francisco Municipal Transportation Agency will close the Twin Peaks Tunnel for a week starting Thursday to perform short-term repairs outlined in a report the agency commissioned earlier this year.
The West Portal and Forest Hill stations will not be open as workers repair the 104-year-old tunnel in two different areas. Transportation officials have previously said workers will install tie rods to reinforce the tunnel ceiling and inject grout into areas of the tunnel with loose soil. The closure will last until Aug. 29, the SFMTA said.
For students in the San Francisco Unified School District, classes began again on August 16, while for students at City College of San Francisco, the first day of classes was August 19. Students at San Francisco State University will return to campus on Monday, August 26.
During the eight-day closure, Muni bus shuttles will operate on the K-Ingleside and M-Ocean View routes between Balboa and Church stations, and will also stop at Castro station. S-Shuttle trains will operate between Castro and Embarcadero stations. The L-Taraval bus route will run from the San Francisco Zoo to Church station. Rail service on the J-Church, N-Judah and T-Third routes will not be affected by the tunnel closure.
SFMTA spokesman Michael Roccaforte said several factors went into choosing the closure date, including avoiding large events, contractor availability and completing necessary repairs before another San Francisco Unified School District project.
The school district plans to begin work on West Portal Elementary School, replacing eight dilapidated bungalows with two new buildings. The school is located above the Twin Peaks Tunnel.
Transport officials have repeatedly said the tunnel is safe for passengers and staff, and the report by engineering firm HNTB recommends that some of the repair work be completed within the next six months.
After repairs are completed, the SFMTA will continue to conduct inspections to evaluate the tunnel’s structure. Additional tunnel work is expected over the next five to 10 years, the SFMTA said.