What is the key difference between stationary and moving radar devices?

The key distinction between stationary and moving radar devices is rooted in their operational context. Stationary radar devices are set up in a fixed location, usually deployed alongside the road, to monitor and measure the speed of vehicles passing by. This allows for consistent measurement from a predetermined spot, where the radar can capture the speed of oncoming traffic directly.

On the other hand, moving radar devices are utilized within a moving vehicle, allowing law enforcement to measure the speed of other vehicles while in transit. This capability provides a dynamic approach, enabling officers to track speeds as they navigate through traffic.

The other options, while they touch on relevant aspects of radar technologies, do not capture the fundamental operational difference that is key to understanding how each type functions in speed enforcement. For instance, the size and weight of the devices can vary, but they do not define their ability to measure speed based on their stationary or moving nature. Similarly, the type of speed measurement technology and calibration methods are critical factors but do not fundamentally differentiate between stationary and moving radar.