California Department of Transportation

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CSMP Document


The US 101 North Corridor is a portion of the only continuous North-South highway west of the Coast Range in Northern California. The corridor serves as the primary freight route through Marin and Sonoma Counties, providing access to other Bay Area goods movement corridors via I-580, and serving as a key access route to San Francisco and coastal Northern California.

The corridor is predominantly freeway with one remaining seven-mile section of expressway between Novato and Petaluma. There are existing HOV lane segments in Marin County and near Santa Rosa. The arterial network is discontinuous due to topography. The cities of Sausalito, San Rafael, Novato, Petaluma and Santa Rosa are the main urban centers along the corridor. The US 101 North Corridor also intersects with SR 1, 12, 37, 116 and 128. 

Corridor Specific Issues

  • US 101 is the only major north/south route connecting San Francisco to Santa Rosa and the North Coast.
  • Primary goods movement corridor for Marina and Sonoma County.
  • Major commute corridor for both San Francisco and Santa Rosa.
  • Local trips forced onto US 101 due to lack of alternative routes and discontinuous arterial network.
  • SMART Rail District planning efforts moving forward for passenger rail from Larkspur to Cloverdale.   

Corridor Mobility Improvement Account (CMIA) Projects 

The CSMP requirement is noted in the Baseline Agreements of all projects receiving CMIA funding. CMIA funds have been allocated for the following improvement project on the US-101 North Corridor:

  • US 101/I-580 Greenbrae Corridor Aux. lane
  • Marin-Sonoma Narrows-Segment A
  • HOV Lanes: Railroad Ave—Rohnert Park Expwy
  • HOV Lanes: Wilfred Ave—Santa Rosa Ave.
  • HOV Lanes: Steele Ln.—Windsor River (North Phase A)
  • Central Project, Phase B
  • Marin-Sonoma Narrows, Phase 2 - Widen Novato Creek Bridge for HOV Lane


For More Information, please contact: 

Joseph Aguilar
Office of System Planning
District 4




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