Highways

Highways are a critical part of Sonoma County's transportation system, with 250 miles of state roads - including Highways 1, 12, 37, 101, 116, 121 and 128.

Highway 101 is the main arterial highway in Sonoma County and upgrading 101 has been the biggest component of Measure M. There are four segments of the project to improve Highway 101, with more detail on the Measure M 101 Project Page.

State Highway Operation and Protection Program (SHOPP): The State of California Department of Transportation (Caltrans) and its partners (including us here at the Sonoma County Transportation Authority) have strategically invested in the State Highway System (SHS) for over a century.  The SHOPP is a Caltrans Program that maintains our investment in the SHS.  For a map and listing of the Caltrans Sonoma County SHOPP projects click here. For an overview of the state wide program review the 2015 10 year SHOPP Plan here. For a state wide listing of active projects go here. For Caltrans GIS of projects click here.

Highway 37 is an example of the increasing need to consider sea level rise when analyzing our infrastructure. Situated along San Pablo Bay amid wetlands and critical habitat, this important corridor is susceptible to flooding during strong winter storms. In planning for the future of Highway 37, the SCTA is working with Caltrans, MTC and the other North Bay counties to explore congestion issues as well as address sea level rise and the likelihood of increased flooding. Read more

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