In a traffic court trial on August 3, 2011, in Marin County, the Court Commissioner agreed with Attorney John Stanko’s argument that a speeding ticket issued on Northbound Nicasio Blvd. in West Marin was illegal. The CHP had cited the driver for allegedly going 55 mph in a 35 mph zone just North of Nicasio Elementary School. The Highway Patrol Officer had used a Radar gun to determine the driver’s speed.
In California the use of Radar on most surface streets must be justified by a valid traffic and engineering survey. California Vehicle Code sections 627 and 40802 et sec. discuss the use of radar to detect the speed of a moving vehicle. Absent the proper introduction of evidence, including a valid certified traffic and engineering survey a peace officer’s use of radar is an illegal speed trap. When the court finds that the use of radar was illegal the officer is incompetent to give testimony and the court is without jurisdiction to render a finding of guilt.
The California Manual on Uniform Traffic Control Devices and the Vehicle Code require that the speed limit be set within the nearest 5 mph of the 85 percentile of drivers in a traffic and engineering survey. Absent proper justification based on factors not readily apparent to drivers, the speed limit may not be reduced lower than the nearest 5 mph of the 85 percentile. In this case the 85 percentile speed was 45 mph but the speed limit had been set at 35 mph without proper justification and the Court had to dismiss the case.