HOW FIXED SPEED CAMERAS WORK
Why there’s no escaping the flash of a speed camera when you break the speed limit
WORDS SCOTT DUTFIELD
Keeping tabs on roads around the world, speed cameras have helped catch lead-footed drivers since 1964 with the invention of the Gatsometer speed camera, or ‘Gatso’. Today’s Gatso speed camera is a radar system that uses radio waves to measure the speed of passing cars. It does this by calculating the time it takes emitted radio waves to return to the camera’s receiver from a moving vehicle, otherwise known as the Doppler effect. As a car passes the speed camera, the frequency at which radio waves rebound increases, which can then be translated into the speed of the vehicle.