Route 1 Tom Lantos Tunnel Full Overnight Closures


District: 4 - Oakland
Contact: Alejandro Lopez
Phone: (510) 385-6856

Of Southbound Tunnel For Construction Work October 13-16

San Mateo County — Caltrans has scheduled full overnight closures of southbound State Route (SR-1) at the Tom Lantos Tunnel (Devil’s Slide) Tuesday, October 13 to Friday, October 16, 2020. Northbound SR-1 tunnel will remain open with intermittent one-way traffic control. The purpose of the closures is to accommodate delivery of a generator and associated equipment. Provisions will be made for emergency vehicle access.

Closure Schedule:

  • Tuesday, October 13 – 08:00 PM to 04:00 AM
  • Wednesday, October 14 – 06:00 PM to 04:00 AM
  • Thursday, October 15 - 08:00 PM to 04:00 AM
  • Friday, October 16 - 08:00 PM to 04:00 AM

Traffic Control Measures:

Changeable message and directional signs will be in place to assist motorists traveling in the area. Flaggers will be on-site to assist with northbound tunnel one-way traffic control. The California Highway Patrol (CHP) will be at the site during the closure.

Detours are as follows:

  • Traffic control will be at Linda Mar (SR-1) - Southbound traffic heading to Half Moon Bay will be requested to turn around and take Sharp Park Road or Skyline (SR-35) to I-280 south.
  • Traffic control at Half Moon Bay (SR-1) - Northbound traffic heading to SanFrancisco will be rerouted to take SR-92 to I-280 north.

Please drive with caution. Slow for the Cone Zone and Be Work Zone Alert. Caltrans thanks motorists for their patience while we work to maintain our state’s highways, bridges, and tunnels.

For 24/7 traffic updates, follow For real-time traffic, click on Caltrans QuickMap: