The California Department of Transportation (Caltrans) in association with the Sonoma County Transportation Authority (SCTA) and the Metropolitan Transportation Commission has started construction work on next phase of $700 million the Marin-Sonoma Narrows Project (MSN) on U.S. Highway 101 in Petaluma, California.
The scope of the project involves upgrading the U.S. 101 from a highway to a freeway. The company will also reconstruct the Petaluma Boulevard South interchange; replace the Petaluma River Bridge; construct or widen nearly three miles of frontage roads.
Caltrans will also provide new pedestrian and bicycle enhancements; replace the northbound State Route 116 Bridge and widen the southbound SR-116 Bridge, which will enable the highway to accommodate future carpool lanes on U.S. 101. The transport department will improve a two lane section of the highway, called The Narrows, to reduce congestion and increase safety.
Caltrans will also undertake several other significant improvements along the highway to improve its transportability. The project is being undertaken to introduce more carpool lanes in future, which will convert the highway into a freeway in future.
The MSN projects in Petaluma were allocated $120 million in funding, including $105 million from Proposition 1B, a 2006 voter-approved transportation bond, and $7 million from Measure M, approved by Sonoma County voters in 2004.