Land vehicles use speedometers to determine speed. That way, drivers can maintain speed levels within the limits of the law. The speedometers rely on rotating cables and magnets to calculate the rate of travel. However, speedometers are not the only available speed measuring equipment.
The police rely on radar speed guns among other equipment to monitor the speed at which drivers drive. The idea is to detect traffic that violates speeding regulations with the hope of saving lives.
The following are commonly used equipment for measuring speed:
Radar speed guns operate on the Doppler effect. Here, the gun bounces sound waves off vehicles and calculates the frequency of the sound wave as it returns to the equipment. The closer the car is to the device, the higher the frequency.
If the Doppler effect is found to be spread, the car was moving at a slower speed and vice versa.
LIDAR (Light Detection and Ranging) equipment measure speed the same way radar does. However, instead of sound, the equipment rely on light. It focuses an infrared beam of light towards the car and measures the time it takes for it to reflect.
Since it relies on light, which travels faster than sound, LIDAR equipment provides readings faster.
Average Speed Computers
The average speed computer uses a stopwatch and an airplane to determine the time it takes a vehicle to move from point A to point B. A computer on board uses an average-speed program to calculate speed. The pilot radios a patrol unit when he notices a speeding vehicle; who then issue the driver a speeding ticket.
Speed detectors are important for ensuring compliance. If a driver knows that their speed goes through monitoring, they are more likely to keep within limits. It pays to have reliable monitoring equipment so that the drivers do not try to wiggle out of a ticket.
For example, you can install radar equipment with cameras that will serve as evidence if it becomes necessary.