Lane Closures Scheduled For Tree Removal as the Marin-Sonoma Narrows (MSN) Construction Continues With Night Work in Marin County


Work scheduled to start Monday, September 26, at 10 p.m.

MARIN COUNTY — The Marin-Sonoma Narrows B-7 construction project continues in September and October with tree removal scheduled to close the far right lane on US-101 in the northbound and southbound directions.

The work will start at the Franklin Avenue overpass in Novato to the Marin-Sonoma county line near Petaluma. For northbound 101, times are 10 p.m. until 7 a.m. For southbound 101, times are 10 p.m. until 5 a.m. The maintenance will occur near the shoulder in both directions, requiring the far right lane to be closed.

The number of lanes vary depending on the location. At least one lane will be open to the public at all times. The work is scheduled to last until on or around October 8.

This is the last remaining High Occupancy Vehicle (HOV) lane construction project as part of the 17-mile US-101 Marin-Sonoma Narrows (MSN) program. This final MSN 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 for 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 county line, and for 6.3 miles along the southbound lanes from De Long Avenue to the county line.

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.

Additional project information is available at:
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Map showing the Southern end of the lane closure for tree removal for the Marin-Sonoma Narrows project.