• Contact Information

    Transportation and Engineering


    Monday - Friday
    7:30 a.m. - 5:30 p.m.

    Contact Us

    100 Jefferson County Pkwy.
    Ste. 3500
    Admin and Courts Facility
    Golden, CO 80419

  • Transportation and Engineering Banner 671x92
  • Speed Limits 

    Speed Limit SignIn Colorado, for roads that are not posted, speed limits are:

    • 20 mph on narrow, winding mountain roads
    • 25 mph in any business district
    • 30 mph in any residential district
    • 40 mph on open mountain highways 

    Speed limits should not be set higher or lower than these limits unless a traffic study has been performed to justify the change. This applies to all state highways, county roads and city streets. The study includes an analysis of roadway conditions and accident records and a count of the prevailing speed of traffic. A safe and reasonable limit is then established at or below the speed at which 85 percent of drivers travel.

    See "Establishing Realistic Speed Limits" on the Colorado Department of Transportation website You are now leaving the jeffco.us website to an external site for more information.

    To report a concern about posted speed limits on county roads, use the online Service Request Form or call 303-271-8461.

    Speed Limit Violations

    Neighborhood speeding problems should be reported to the Jefferson Sheriff's Office Traffic Unit at 303-271-KOPS (5677).

    Last Updated: 6-8-2017