Which technology is often used to enforce speed limits on roads?

The technology that is commonly used to enforce speed limits on roads is RADAR. RADAR operates by emitting radio waves to detect the speed of moving vehicles. It works by measuring the time it takes for the emitted waves to return after bouncing off an object, such as a car. When the waves reflect back, the system calculates the speed of the vehicle based on the frequency shift of the returning waves, known as the Doppler effect. This technology allows law enforcement officers to accurately determine whether a vehicle is exceeding the posted speed limit.

RADAR systems are portable and can be set up in various locations, making them highly effective for traffic enforcement. They provide objective and reliable data that can be used in traffic citations and for monitoring overall traffic patterns. This effectiveness and accuracy make RADAR the preferred choice for speed limit enforcement, distinguishing it from other technologies listed.

While Closed-Circuit Television (CCTV) can be used for surveillance and monitoring traffic patterns, it is not specifically designed for speed enforcement. GPS tracking can provide location data but does not usually serve to enforce speed limits directly. Smart traffic lights manage traffic flow but are not utilized primarily for speed enforcement.