Ramp, Lane Closures on Northbound, Southbound US-101 as Part of Marin Sonoma Narrows B7 Project in Marin County

Schedule: Monday, Aug. 3 to Friday, Aug. 7 from 8:30 p.m. to 6:30 a.m.

Marin County - Caltrans has scheduled ramp and lane closures for final striping on Northbound and Southbound US-101 for the Marin Sonoma Narrows B7 project from Monday, Aug. 3 through Friday, Aug. 8 from 8:30 p.m. until 6:30 a.m. the next mornings.

The schedule for ramp closures is as follows:

Monday, Aug. 3 through Friday, Aug. 7: The San Antonio on- and off-ramps on Northbound and Southbound US-101 will be closed.

Wednesday, Aug. 5 through Friday, Aug. 7: The Atherton Avenue and De Long Avenue on- and off-ramps on Southbound US-101 will be closed.

This is the last remaining High Occupancy Vehicle (HOV) lane construction project as part of the 16-mile US-101 Marin-Sonoma Narrows (MSN) program. This project has completed and allows continuous HOV lanes on US-101 from Sausalito in Marin County to Windsor in Sonoma County.

All work is weather dependent.

Detours for San Antonio on-ramp closures on US-101

• Northbound: Drivers must enter on US-101 southbound at San Antonio Road, exit at the Atherton Avenue off-ramp and then re-enter US-101 northbound.
• Southbound: Drivers should take Northbound US-101 and exit at Kastania Road, turn left and re-enter Southbound US 101.

Detours for San Antonio Road off-ramps on US-101

• Northbound: Drivers must exit at Petaluma Boulevard South/ Kastania Road, enter US-101 southbound, and exit at San Antonio Road
• Southbound: Drivers should continue southbound and exit at Atherton Avenue, turn left and enter Northbound US-101 to get to the San Antonio off-ramp.

Detours for De Long on-ramp and off-ramp closures on Southbound US-101

• On-ramp: Drivers should travel Southbound on Redwood Boulevard and enter Southbound US-101 at Rowland Boulevard.
• Off-ramp: Drivers should exit at Atherton Avenue and then use Redwood Boulevard to reach De Long Avenue.

Detours for Atherton Avenue on and off-ramp closures on Southbound US-101

• On-ramp: Drivers should travel Southbound on Redwood Boulevard and enter US-101 at De Long Avenue
• Off-ramp: Drivers should exit at De Long Avenue, turn right and use Redwood Boulevard.