Determining Speed Limits

Share & Bookmark, Press Enter to show all options, press Tab go to next option
Print

When a new roadway is constructed or an existing roadway undergoes a significant change in surrounding land use or roadway characteristics, the City of Brentwood is required to perform a speed survey in accordance with the California Vehicle Code (“CVC”) and California Manual of Traffic Control Devices (“MUTCD”). A speed survey consists of measuring speeds with a radar gun of 100 vehicles in each direction on any given roadway segment. These measurements must be taken when traffic is flowing freely in fair weather with no unusual conditions present.

The speed limit for any segment of road is set at the nearest 5 miles per hour (“mph”) increment of the 85th percentile speed of the speed survey. The 85th percentile speed is that speed at which 85% of the vehicles are traveling. For example, an 85th percentile speed of 41.5 on a speed survey would establish a speed limit of 40 mph, whereas an 85th percentile speed of 43.8 on a speed survey would establish a speed limit of 45 mph. An additional reduction of 5 mph may be taken if the Traffic Engineer feels it is warranted to meet the traffic safety needs of the community.

After the speed limit is adopted by the City Council and appropriate signs installed, the Police Department can legally enforce the posted speed limits with the use of radar. If no physical changes occur on the roadway, the speed survey is considered valid for a period of 7 years, and can be extended up to 10 years if conditions remain constant.

Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Download Acrobat Reader Windows Media Player Download Windows Media Player Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer