Highway 101 Widening in Petaluma
Caltrans is widening Highway 101 in Petaluma between Lakeville Highway (Route 116) and Corona Road by adding a carpool lane in each direction. Upon completion, Highway 101 will be three lanes in each direction, including the new northbound and southbound carpool lanes. Ghilotti Construction is the contractor on the $78 million project. The project is scheduled for completion in late December 2023.
The Petaluma project, known as C2, is the final project in Sonoma County and will be the eleventh project to be completed. The remaining widening projects in Marin County will begin is spring 2022.