Nightly closure of Twin Peaks Tunnel for inspection starts late next week

Jerold Chinn
2 min readSep 8, 2023
Photo via SFMTA.

San Francisco transit officials said that the 105-year-old Twin Peaks Tunnel will undergo final inspection work of the tunnel’s ceiling next week, leading to a temporary nightly closure for maintenance work beginning late next week.

Starting Sept. 14 and lasting until Sept. 21, the San Francisco Municipal Transportation Agency will close the tunnel between West Portal and Castro stations from 9 p.m. until midnight, Director of Transportation Jeffrey Tumlin said Tuesday at the SFMTA Board of Directors meeting.

During the closure, bus shuttles will supplement service on the K Ingleside and M Ocean View on the street level between Church station and Balboa
Park station. The L Tarava bus will run between Church station and the zoo while the J Church, N Judah and T Third will not be affected by the tunnel closure.

Passengers traveling downtown can catch an S Shuttle train either at Castro or Church stations, the SFMTA said.

Tumlin said crews will be climbing into the “plenum space” or the space between the flat ceiling and outer structure of the tunnel to do the inspection.

Any recommendations for repair work, if any, will be made based on the findings, he added. A report will come back to the board for review in a few months.

The SFMTA had previously closed the tunnel during the weekend in April to inspect the tunnel’s ceiling.



Jerold Chinn

I am a freelance reporter in San Francisco with over a decade of experience covering transportation in the city. Bylines include SFBay and The Ingleside Light.