Speed Limit Establishment

Speed limits are set by the city’s traffic engineer to regulate driving behavior and keep motorists travelling at safe speeds.

Most residential roads you drive on in the city are defined as local roads which have a prima facie speed limit of 25 miles per hour unless otherwise posted. Speeding through residential areas creates unsafe conditions. When residents feel motorists are unsafely driving through their neighborhood, they call us and ask for help. If we determine that speeding is a chronic problem, we follow the guidelines of our Neighborhood Traffic Management Plan to restore traffic safety.

Prima Facie Speed Limits

Prima facie speed limits are established by state law and are included in the California Vehicle Code. They do not require the posting of speed limit signs because they are understood to be the default speed limit due to the characteristics of the road. Drivers in California must demonstrate knowledge of these speed limits to obtain a license.

Some of the prima facie limits are:

  • Local Streets
  • Business Districts
  • Senior Centers
  • School Districts (when school children are present)
  • Alleys
  • Entering Intersections where no traffic control devices are used
  • Railroad Crossings where visibility is limited and no gates, flagmen or signal warnings control the crossing

Establishment of Posted Speed Limits

The City of San Mateo establishes speed limits for City streets by criteria established by the State of California Department of Transportation and published in the California Vehicle Code. Speed limits are set through speed surveys that are conducted for streets where the prima facie speed limit would not be applicable such as collector or arterial streets.