LIDAR technology operates on the “time of flight” or “Time-Distance” principle. The laser units transmit infrared light pulses at a moving object. Since the speed of light is known, it is possible to ascertain the distance of an object by the time it takes for a beam to bounce off an object and return. Changes in that distance over time provide the vehicle’s speed, a computation that is based on an average of hundreds of laser light pulses hitting the object in a fraction of a second.

When used for speed or distance measurement, laser devices are also known by the name LIDAR (an acronym for Light Detection and Ranging) technology. Speed measuring lasers are also sometimes referred to as a laser speed measurement device (LSMD). LIDAR devices are often used in high traffic areas, since the laser beam can easily focus on individual vehicles, allowing pinpoint accuracy. The officer can accurately measure the speed of a vehicle, even in heavy traffic.

Rules for operating LIDAR technology as traffic lasers vary from state to state. Always refer to your own state’s guidelines for specific requirements in your region.