• Speed Limit 3

Speed Limits

A Speed Limit refers to the maximum speed permitted for vehicle travel, and is generally posted on a road sign. Speed limits are designed to prevent operation of vehicles at reckless or otherwise unreasonable speeds; violation of the speed limit can result in a citation or collision.


Who enforces speed limits?

Speed limits are enforced by law enforcement agencies such as the California Highway Patrol (CHP) or Sonoma County Sheriff's Office.

Request Enforcement

When motorists are consistently violating the posted speed limit in a given area, local residents often feel that lowering the speed limit will help slow people down. In fact this is usually not the correct solution. The best course of action is to contact CHP and request enhanced enforcement of the existing speed limit. When doing so, be sure to provide the days of the week and specific times of the day that you have observed the most violations.

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: An Informational Report

If you believe that a speed limit should be changed, please contact us at (707) 565-2231. Please note, we cannot guarantee that your request will be granted. Engineering staff need to assess the situation to make a determination, and all new speed limits or changes to existing speed limits must be 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.

Map of County Speed Limits

See full-screen map
Speed Limit 125 or LessSpeed Limit 230 or 35Speed Limits 340 or 45Speed Limits 450 or 55

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

Traffic Engineering - Related Pages

Traffic Enforcement Agencies