Schedule: Monday, Jan. 29 to the morning of Saturday, Feb. 3, 10 p.m. until 5 a.m.
MARIN COUNTY — The Marin-Sonoma Narrows B-7 construction project continues in January and February with new lights and metering system work, which requires the Atherton Avenue on-ramp and off-ramp to be closed on Southbound US-101 in Novato.
The on-ramp is scheduled to be closed Monday, Jan. 29 through Friday, Feb. 3 from 10 p.m. until 5 a.m. the next mornings.
The off-ramp is scheduled to be closed Wednesday, Jan. 31, Thursday, Feb. 1 and Friday, Feb. 2 from 10 p.m. until 6 a.m. the next mornings.
On-ramp closure detour
Drivers can take Redwood Boulevard and enter Southbound US-101 at the De Long Avenue on-ramp.
Off-ramp closure detour
Drivers should go south on US-101 to the De Long Avenue exit where they can come back around on Redwood Boulevard.
Daytime access near Atherton Avenue will be open.
All work depends on weather.
Changeable message and directional signs will be in place to assist motorists traveling in the area. The California Highway Patrol (CHP) will be on-site during the closures.
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 will complete and allow continuous HOV lanes on US-101 from Sausalito in Marin County to Windsor in Sonoma County. HOV lanes are scheduled to be open to use in the summer of 2025.
Construction includes widening US-101 to install HOV lanes for 3.5 miles along the northbound lanes from North Novato to the Marin, Sonoma line, and for 6.3 miles along the southbound lanes from De Long Avenue to the county line.
On June 10, 2023, Caltrans diverted Southbound US-101 traffic onto new elevated lanes spanning San Antonio Creek to just north of Atherton Avenue in Novato. This was a major milestone for the project.
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 511.org: https://twitter.com/511SFBay
For real-time traffic, click on Caltrans QuickMap: http://quickmap.dot.ca.gov/