Road Data & Resources
Transportation and Public Works is now Sonoma Public Infrastructure - Website updates coming soon!
Utilities and other construction companies are required to conform to Sonoma County Construction Standards when doing any construction on Sonoma County roads.
Find out how streets and highways are categorized according to the volume, connectivity, and intended usage.
Browse through maps to see road-related geographic features, such as project locations, road closures, pavement condition, and more.
Planning & Reports
Go here to find important documents released by the Department of Transportation & Public Works Roads Division.
Find about about the County post mile system. Download the Sonoma County Postmile Book, a reference guide to locations along County roads.
View/Download Postmile Book (PDF)
See total miles within the County-maintained road system, broken down into categories.
State, County, City or private? Find out how to know which agency is responsible for which road.
See information about vehicle speeds and traffic volume on Sonoma County roads.