Best Practices for Radar Speed Sign Installation

These guidelines and recommendations provide the best practices for radar speed sign installation to assure successful, accurate and effective traffic calming.


Prior to the radar speed sign installation, look for any obstructions that might interfere with proper operation of the sign (telephone poles, large tree limbs, other signage, etc.).


The radar speed sign should be installed no more than 5 feet from the road curb. Signs placed more than 5 feet from the road will result in displayed speeds that are LOWER than the actual speed.


Do not install the radar speed sign in a curve or after a curve. The sign should be installed in a straight section of road. A radar speed signal cannot “curve” with the road, and will not display speeds with enough time for drivers to see the alert and adjust their speed.


For maximum vehicle detection the radar speed sign should be positioned perpendicular to the road with the radar pointing directly at the curb in the direction of oncoming traffic, not at the center of the road. Signs rotated toward the center of the road will not perform as well.


SOLAR MODELS | Do not install a solar powered radar speed sign under a tree. Summer leaves on the tree could impact solar recharging. Make sure the solar panel is installed facing as close to South as possible at a 45° angle.


The radar speed sign should be installed on the same side of the street as oncoming traffic. If installed on the opposite side of the road, the angle of the sign could result in poor detection of the oncoming traffic.


The bottom of the radar speed sign should be installed 7-10 feet off the ground. Installing lower than 7 feet will reduce the detection range resulting in much of the radar speed signal being absorbed by the road.


For streets with street parking: To prevent the radar signal from being blocked by parked vehicles, the radar speed sign should be installed high enough off the ground to detect oncoming traffic over the parked vehicles.


If the radar speed sign is installed more than 12 feet above the roadway, the sign should not be tilted more than 3°- 4° downward to detect vehicles. Doing so will greatly reduce the length of time vehicles are detected and will display speeds that are LOWER than the actual speed.


Best Practices for Radar Speed Sign Installation PDF