VIDEO: Twin Peaks Tunnel Service to be Restored this Weekend

K, L and M service is scheduled to return to normal this weekend. First and foremost, we want to thank all Muni riders, the construction crews, neighbors, merchants, and SFMTA staff for bringing this project in on time and within budget. Your patience means we can all enjoy new tracks and a safer Tunnel for generations to come.

After two months of construction, the 100-year-old Twin Peaks Tunnel project plans to reopen—meaning regular service resumes at West Portal and Forest Hill stations. Trains will once again run along the K, L and M lines. Right now, our crews are finalizing the last round of testing to make sure everything is up and running reliably. The Nx will resume service on Monday, August 27th.

The tunnel's infrastructure including the tracks, walls and drainage systems were updated to keep up with the demands of the Muni system. With new tracks, the tunnel’s previous speed restriction will be lifted and will keep trains running reliably through the system. Seismic reinforcements and fire safety enhancements were completed to better protect the tunnel’s overall structure and stability.

Last but not least, four new track crossovers were installed in the tunnel that will allow the train to switch from one track to the other during delays and can assist improving overall train operations by adding flexibility to our system.

Later this fall after the tunnel is operational again, there will be two more planned weekend overnight closures to West Portal, Forest Hill, Castro and Church stations. These closures will only be in effect at night -- when ridership is low -- and are scheduled from approximately 11:59 p.m. to 8:00 a.m. on two Friday/Saturday and Saturday/Sunday nights still to be determined. Bus shuttles will be provided while these additional electrical upgrades are done. We’ll keep you updated right here on Moving SF. Be sure to sign up for real-time alerts as well.

For more information on this project, visit our webpage.