Petaluma Highway 101 widening project progressing with new stage next week

Work is progressing on a freeway widening project on Highway 101 in Petaluma, and the next stage will next week involve closing the northbound lanes of the freeway between Lakeville Highway and the Corona overpass.

The lanes will be closed between 10 p.m. Thursday, Jan. 14 and 6 a.m. Friday, Jan. 15 to allow work crews to shift northbound traffic onto temporary lanes constructed in the median. 

The northbound closures will be staggered during the night to accommodate the traffic shift. One northbound lane will always be open. The temporary lanes are standard width and will not reduce freeway capacity. Southbound traffic will not be affected.

The work schedule will depend on dry weather and could be delayed by rain. 

The traffic shift is part of a project to widen Highway 101 by adding a carpool lane to both directions, creating a six-lane freeway of three lanes in each direction. Shifting northbound traffic onto the former median creates room for Caltrans to reconstruct and widen the outside bridge lanes, kicking off Stage 2 of the widening project.

The northbound traffic shift will allow Caltrans to demolish and rebuild an elevated freeway section called the Petaluma Overhead. Northbound work is expected to be completed by the end of 2021 with project completion in 2023. 

The project is one of 13 projects in the larger Marin/Sonoma Narrows widening project to add a carpool lane in each direction of Highway 101 between Highway 37 in Marin County and Corona Road in northern Petaluma.

To visit the project webpage, click here.