What type of measurement does radar provide for the speed of a suspected speeder?

Radar provides a measurement of speed that is often referred to as "on the spot" because it captures the speed of a vehicle at the exact moment the radar system is activated. When a radar device is used to monitor traffic, it emits radio waves that reflect off moving vehicles. The device calculates the speed based on the change in frequency of the returned waves using the Doppler effect. This allows law enforcement officers to obtain instantaneous speed readings of a suspect vehicle, making it a reliable tool for speed enforcement.

In the context of law enforcement and roadway safety, the capability to measure speed in real-time at the moment the infraction occurs is critical. It enables officers to make informed decisions based on the speed recorded at that specific point in time, rather than relying on averages or estimates that could introduce inaccuracies.

While options like "real-time accurate" may sound plausible, they do not fully encapsulate the nature of the measurement being instantaneous as identified in "on the spot." Additionally, a calculated average or estimated maximum speed would imply measurements taken over a period or using various methods that can introduce delay or uncertainty, which is not the case with radar's immediate speed reading.