Twin Peaks tunnel shutdown to affect weekend Muni Metro service

Muni Metro subway service will be partially closed this weekend on April 15 and 16 so the San Francisco Municipal Transportation Agency can perform a detailed structural inspection of the 105-year-old Twin Peaks Tunnel.

Jeffrey Tumlin, SFMTA director of transportation, said last week at the agency’s Board of Directors meeting:

“In order to complete this work we’ll need at least 51 continuous hours of testing. The most effective way to do that is to do it all at once, working for 24 hours in the subway over a weekend.”

A SFMTA advisory said shuttle buses will run in place for the K-Ingleside and M-Ocean View between Balboa Park and Church stations. Additionally, the L-Taraval bus route will extend to Church station, Tumlin said.

Passengers heading downtown can connect to the J-Church and N-Judah at Church Street as service on the J and N will not be affected by the tunnel inspection. Passengers who need to head back west, can catch the K, L, M shuttle buses at either Church or Castro stations.

S-Shuttle trains will provide additional service in the subway between Castro and Embarcadero stations.

In answering a question by SFMTA board Director Steve Heminger about whether there was an issue in the tunnel that needed immediate attention, Tumlin said the tunnel was safe for use, but that it was time for the tunnel’s “big inspection.”

Tumlin said that the tunnel was safe for use, but added that there “may be an increase in fine cracks” in the tunnel. He added that the agency knows the tunnel is due for major rehabilitation work and that the inspection and report from the inspection will further help staff understand the condition of the tunnel and what additional work might be needed.

Last month, the agency completed another quarterly round of subway improvements during the late evening hours during Fix It! Week where crews focused more on special track work, Tumlin said.