Long-delayed Twin Peaks Tunnel repair work is finally on track again, and that means reroutes affecting some 81,000 daily transit riders.
For the thousands who rely on Muni’s K-Ingleside, L-Taraval and M-Oceanview light-rail lines, shuttles will replace normal service during the planned Twin Peaks Tunnel construction, with transfers to other buses needed to arrive at some regular destinations.
The work was originally slated to start last fall, then again in January, and now finally the San Francisco Municipal Transportation Agency quietly announced last week that track-work on the 100-year-old tunnel will begin in April.
“The delay was due to additional outreach to the West Portal neighborhood and merchants regarding construction impacts around the West Portal station,” said SFMTA spokesperson Paul Rose.
That work is to “extensively rehabilitate” tunnel infrastructure that’s more than 40 years old, some of which dates back to the original Twin Peaks Tunnel construction in 1917. SFMTA plans to replace the tunnel’s tracks and track switch systems, repair concrete walls and seismically retrofit the tunnel.
The Twin Peaks Tunnel is a vital connector between the west side of The City and downtown, serving some 81,000 daily riders on the K, L and M lines each day, all of whom will need to adjust to a new, temporarily altered commute.
There will be five scheduled shutdowns to complete the tunnel rehabilitation, each lasting 11 to 15 days long. The construction schedule is not yet finalized, according to the SFMTA, and “will be published shortly.”
Preliminarily, at least, the SFMTA wrote on the tunnel construction website some advisories for the reroutes: L-Taraval shuttle buses will run between Castro Station and the San Francisco Zoo, and serve all regular L line stops between the zoo and 14th Avenue. Buses will then operate express between 14th Avenue and Castro Station with a stop at Forest Hill Station.
M-Oceanview shuttle buses run between Castro and Balboa Park stations, but won’t stop at Forest Hill Station, as the trains do, and will require transfers.
The K-Ingleside will operate as trains between St. Francis Circle and Balboa Park, according to the SFMTA, but those traveling downtown are advised to transfer at Balboa Park Station to BART instead.