Speed Limits


Traffic Speed Survey

Speed Survey (County-maintained roads only)

Speed Limits Ramp

County Speed Limit (15 to 55 Miles Per Hour)

Alternate Views of the Map

Miles Per Hour

Speed Limit 125 or LessSpeed Limit 230 or 35Speed Limits 340 or 45Speed Limits 450 or 55

Map Information

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.

Contact Information

Business Hours
Monday – Friday
8:00 AM – 5:00 PM
Contact us by Phone
Office Location
La Plaza B
2300 County Center Drive
Suite B 100
Santa Rosa, CA 95403
38.462023, -122.725381

Interactive Maps

Sonoma County Interactive Maps


Thematic interactive maps for Sonoma County