Overnight lane and ramp closures are scheduled along US-101 in San Rafael and southern Marin County through Saturday morning.

The closures were scheduled to begin Monday, Oct. 19, and run nightly through the morning of Saturday, Oct. 24, according to a Caltrans traffic advisory. Crews are repaving and restriping a 7.3-mile stretch of highway from Wornum Creek Undercrossing to Miller Creek Bridge as part of a Capital Preventive Maintenance project that was scheduled to begin in mid-May 2026.

Various northbound and southbound lanes will close from 10 p.m. to 6 a.m. each night. Eight ramps are also scheduled to close, with hours varying by location:

  • Northbound on-ramp from Redwood Highway: 10 p.m. to 6 a.m.
  • Northbound off-ramp to Industrial Way: 8 p.m. to 6 a.m.
  • Northbound on-ramp from Industrial Way: 10 p.m. to 7 a.m.
  • Northbound off-ramp to Sir Francis Drake Boulevard: 11 p.m. to 6 a.m.
  • Northbound off-ramp to Second Street: 10 p.m. to 6 a.m.
  • Northbound off-ramp to North San Pedro Road: 10 p.m. to 6 a.m.
  • Northbound on-ramp from Lincoln/Villa Avenue: 8 p.m. to 5 a.m.
  • Southbound off-ramp to Francisco Boulevard: midnight to 4 a.m.

Caltrans has posted detour routes for three of the closures. Drivers turned away from the northbound Redwood Highway on-ramp should follow Redwood Highway south to Tamalpais Drive and merge onto northbound US-101 from there. Those blocked at the Lincoln/Villa Avenue on-ramp can continue on Lincoln Avenue to Mission Avenue or take North San Pedro Road to reach the highway.

Drivers should follow posted detour signs around closed ramps.

Bus stops along the affected ramps may also be affected.

The paving project covers about 54.2 lane miles of roadway and includes pavement grinding, shoulder repairs, guardrail upgrades and new striping, according to the Caltrans project page. The target completion date is summer 2027, weather permitting.

Matt O'Donnell, Caltrans' Marin County public information officer, is the project contact and can be reached at (510) 852-5113. Drivers can check real-time conditions at quickmap.dot.ca.gov or call 1-800-427-7623 for state highway updates.