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About Us

Transportation and Public Works is now Sonoma Public Infrastructure - Website updates coming soon!

The Roads Division of Transportation and Public Works is responsible for the construction, operation, and maintenance of the Sonoma County-Maintained Road System. This includes most public roads within the unincorporated areas of Sonoma County (but does not include state highways, city streets, or private roads). See more information about road jurisdictions

Our mission is to provide the public with the highest level possible of safety, efficiency, and quality of travel.

What We Do

Pavement Preservation

Sonoma County's Pavement Preservation Program is an ongoing effort to improve the quality of Sonoma County county roads by administering large-scale pavement treatment projects. TPW uses a long-term, network-level management approach designed to utilize limited funding as efficiently as possible.

More about Pavement Preservation

Road Maintenance

Sonoma County Road Maintenance crews work every day to keep roads safe and passable. Maintenance of the Sonoma County road system entails a vast array of work, including repair of damaged pavement, cleaning and repair of road signs, removal of roadside vegetation, repair of slip outs and landslides, as well as responding to public requests.

More about Road Maintenance

Bridge Retrofits

Engineering, construction, and maintenance of bridges on County roads is administered by the Roads Division of the Department of Transportation & Public Works.

More about Bridges

Traffic Engineering

Engineering, construction, and maintenance of street lights, signs, traffic signals, pavement markings, and other devices used to regulate traffic and reduce danger on the road.

More about Traffic Engineering

Roads Funding

TPW’s Roads Division maintains the County’s 1,380 mile road network through activities such as pavement preservation (large-scale paving projects), corrective road maintenance (pot hole repair, brush cutting, etc.), bridge retrofits, and various other road safety and improvement projects. Maintaining public roads is a costly endeavor, and funding can come from a number of different sources, depending on the type of activity:

Pavement Preservation

  • Sonoma County General Fund
  • Solid Waste Franchise Fees and Aggregate Mitigation Fees
  • Federal Grants

Corrective Maintenance

  • State Highway User Tax (Gas Tax)
  • Sonoma County General Fund
  • Measure M Funds for Local Streets Rehabilitation

Bridge Projects

  • Federal Funding
  • State Seismic Retrofit funds
  • Measure M Funds for Local Streets Projects

Traffic & Safety Improvements

  • Competitive Federal Grant funding
  • Measure M Funds for Local Streets Projects
  • Traffic Mitigation Funds (traffic mitigation funds can be used to improve traffic flow around new construction).

Read more about funding sources


State Highways

State Highways, including Highways 1, 12, 37, 101, 116, 121, and 128 are part of an interconnected state highway system, built and maintained by the California Department of Transportation (Caltrans). The Sonoma County Department of Transportation and Public Works has no jurisdiction over the California State Highway System.

County Roads

The County, or Unincorporated, Road System makes up the majority of roads within Sonoma County. This includes most roads that are (a) publically-owned, (b) publically-accessible, (c) outside of city limits, and (d) not part of the State Highway System. These are owned and maintained by the Sonoma County Department of Transportation and Public Works.

City Streets

Public roads belong to the city if they are within city limits and not part of the State Highway System. The Sonoma County Department of Transportation and Public Works has NO jurisdiction over city streets.

Private & Other Streets

Some roads may be privately-owned or administered by other agencies. Roads often fall under this category if they are inside any of the following areas: public parks, gated and/or private communities, farms, ranches, wineries, military installations, schools and/or universities.