no
There are no such laws. A police officer can check your speed anywhere along the roadway. If you're in excess of the posted speed for that stretch of road, and they pull you over, it's a ticket.
Doppler radar
radar waves.
Yes, they do it all the time.
A police radar detector is a device used by drivers to detect when law enforcement officers are using radar guns to measure vehicle speed. When a radar gun is detected, the device alerts the driver so they can adjust their speed accordingly to avoid getting a speeding ticket. However, it is important to note that using radar detectors is illegal in some jurisdictions.
Having a radar detector will alert you when a Police Car with its speed radar is near. The Radar Detectors will produce an audible signal alerting you of this, and will do so far in advance of when you are able to see the Police Car.
The answer is "yes." Traffic radar monitors both the speed of the vehicle in which is it mounted and the speed of "target" vehicles coming toward or moving away from it. On the radar display, the officer sees two speeds: "patrol" (the speed of his vehicle) and "target" (the speed of the vehicle the radar is tracking). the target speed measurement is equally accurate, whether the patrol vehicle is moving or not.
With correct application, traffic radar reads true speed or lower than true speed virtually 100% of the time.
A radar gun police use to check for speeders.
The purpose of a Whistler radar detector is to detect the speed of the motorists, if it is being monitored by police or law enforcement by a radar gun.
The Escort Radar Detector scans for the radio frequency waves of most police department speed guns. These speed gun frequencies can be detected for about a mile before actually seeing the police officer.
Yes, some police vehicles are equipped with rear-facing radar units that can detect the speed of vehicles behind them. This allows police officers to monitor and enforce speed limits for vehicles approaching from the rear.