Speed Survey (County-maintained roads only)
County Speed Limit (15 to 55 Miles Per Hour)
Alternate Views of the Map
The above map displays speed limits (linear features) and speed surveys (point features) on County-maintained roads. NOTE: Roads that are within city limits, state highways, or private property do not belong to the County-Maintained Road System.
Setting Speed Limits
Speed limits are set using the guidelines set forth by the Federal Highways Administration (FHWA), as well as on-site assessment by professional civil engineering staff.
FHWA - Engineering Speed Limits
FHWA - Methods and Practices for Setting Speed Limits
If you believe that a speed limit should be changed, please note we cannot guarantee that your request will be granted. Engineering staff need to assess the situation to make a determination. All new speed limits or changes to existing speed limits must be supported by a speed survey, and approved by the Sonoma County Board of Supervisors.
If you are seeking to lower a speed limit in your area due to frequent speeding violations, the more appropriate solution is to contact the California Highway Patrol to request enhanced enforcement.