09/29/2025 | Press release | Distributed by Public on 09/29/2025 15:00
Marin County - Caltrans has opened the long-awaited, continuous HOV lanes (third lanes) on Northbound and Southbound US-101 Monday, Sept. 29 around 5 a.m. as part of the Marin Sonoma Narrows B7 project.
Crews worked overnight on the weekend with striping operations.
This work removed merges on Northbound US-101 (just north of Atherton Avenue) and Southbound US-101 (south of Kastania Road), which opened three continuous lanes through the Marin Sonoma Narrows B7 project.
Work is scheduled to continue at night on Northbound US-101 from Monday, Sept. 29 through Saturday, Oct. 4 between 8:30 p.m. and 7 a.m. the next mornings.
Lanes are scheduled to be closed on Northbound US-101 in that time period. At least one lane will be open for traffic.
The San Antonio Road on- and off-ramps on Northbound US-101 are scheduled to be intermittently closed during that same time frame. Consecutive ramps will not be closed at the same time.
Detour for on- and off-ramp closures on Northbound US-101
All work depends on weather. Daytime access will be available for motorists.
Construction for the project 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.
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.
For 24/7 traffic updates, follow 511.org: https://twitter.com/511SFBay For real-time traffic, click on Caltrans QuickMap: https://http://quickmap.dot.ca.gov/
| CleanCA.com | #BeWorkZoneAlert | Twitter | YouTube |