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Twin Peaks Tunnel Construction and Reopening Update

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Construction vehicle and workers inside illuminated subway tunnel with exposed track infrastructure.

The End is in Sight!

Construction on the 2.2 mile long Twin Peaks Tunnel is nearing completion and crews are still on schedule to finish within the 2-month project window. Current projections show the tunnel being operational on or before the targeted August 25th date. Once reopened, the 80,000 daily riders of the K, L and M lines will get enjoy riding on new rails in the upgraded tunnel.

As we learn more and finish the vital safety and infrastructure upgrades, it will be possible to share a more exact date and time when rail service will resume. Before trains begin running, crews expect a few days of testing and cleaning to be sure all the new equipment is ready to go.

Tunnel Work Progress Report:

  • The new rails in outbound direction are complete and the tracks in the inbound direction are nearly finished.
  • About 90% of the seismic retrofit work is complete.
  • The 100-year old drainage system is 99% upgraded.
  • All four of new track crossovers are installed -- These crossovers help the train switch from one track to the other during breakdowns and can assist improving overall train operations by adding flexibility.
  • Important fire safety enhancements are being implemented.
  • Signal improvements for the trains are approximately 75% complete.

For more pictures, updates and a video about construction in the tunnel, check out our recent blog post.

Later this summer/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 be at night only -- 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.


Construction Update Photo Gallery

As crews begin to wind down construction, be sure to go check out the work and support local business near the work zone on West Portal Avenue between Ulloa and Vicente.

West Portal Avenue pedestrian area with wooden barriers and Open for Business signage promoting local merchants.

Wayfinding signs support local merchants and custom pedestrian barriers keep people safe while allowing a viewing window to the construction site.

Work train loaded with construction equipment and machinery on West Portal Avenue street.

Equipment is loaded in and out of the tunnel with a "work train" that carries materials on the tracks.

Construction workers in safety vests and hard hats inspect structural work inside a transit tunnel with concrete pillars and overhead infrastructure.

Crews inspect the seismic work in the tunnel near the no-longer-in-use Eureka Valley Station.

For more information, see the project website:

https://www.sfmta.com/TwinPeaks