A laser can clock your speed in under half a second 😯 Police use LIDAR speed guns, which stands for Light Detection and Ranging, to pinpoint a single vehicle and measure its exact speed. The device sends out a focused laser beam that bounces off your car, and by calculating how long the light takes to return, it determines your speed with remarkable accuracy, down to fractions of a mile per hour. Unlike radar, which casts a wide signal that can pick up multiple vehicles, LIDAR is precise enough