Road Data & Resources

Construction Standards

Utilities and other construction companies are required to conform to Sonoma County Construction Standards when doing any construction on Sonoma County roads.

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Functional Classification

Find out how streets and highways are categorized according to the volume, connectivity, and intended usage.

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Interactive Maps

Browse through maps to see road-related geographic features, such as project locations, road closures, pavement condition, and more.

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Planning & Reports

Go here to find important documents released by the Department of Transportation & Public Works Roads Division.

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Postmiles

Find about about the County post mile system. Download the Sonoma County Postmile Book, a reference guide to locations along County roads.

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View/Download Postmile Book (PDF)

Mile Totals

See total miles within the County-maintained road system, broken down into categories.

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Road Jurisdiction

State, County, City or private? Find out how to know which agency is responsible for which road.

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Traffic Surveys

See information about vehicle speeds and traffic volume on Sonoma County roads.

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