Laser speedometers use the principle of laser ranging. Laser ranging is to determine the distance between the measured object and the test point by emitting a laser beam to the measured object, receiving the reflected wave of the laser beam, and recording the time difference.

Laser speed measurement is to perform laser ranging on the measured object twice with a specific time interval, obtain the moving distance of the measured object during the period, and thus obtain the moving speed of the measured object. Laser speed measurement has the following characteristics:

(1) Since the laser beam is basically a ray, the speed measurement distance is farther than the effective distance of radar speed measurement, and can be measured 1000m away;

(2) The speed measurement accuracy is high, with an error of <1km;

(3) The laser beam must be aimed at a plane reflection point perpendicular to the laser beam. If the measured vehicle is too far away and in motion, or the vehicle body is not large, the success rate of laser speed measurement is low and difficult, especially for on-duty police officers, who have a high workload and are prone to fatigue.

(4) Laser speed meters cannot be used in motion. They can only be used in a stationary state. Therefore, laser speed meters cannot be called "mobile electronic police". When used in a stationary state. It is easy to be discovered by the driver. Therefore, it cannot achieve the intended purpose.

(5) It is expensive. The price of a laser speed meter imported through formal channels (excluding the viewing and control parts) is at least around US$10,000.