Radar Detectors are one of those devices that are enabling users to outdo or evade the law and that should have instigated their banning. That is not the case even if there is a ban in few states like DC and Virginia. In most states they are not regulated per se, but in almost all states they are not allowed to be used on commercial vehicles weighting more than 10,000 pounds even if this rule might vary a bit from one locality to the other. Nonetheless, the law prohibits any use of a radar detecting system on any commercial vehicle.
Yet, there is no law that bans the manufacturing of the equipment that sells between $30 and $1200+ whose sole use is detecting police radar guns. There are an estimated 100,000 traffic radar guns deployed around the US and they are responsible for more than 30 million speeding tickets issued in a yearly basis.
In fact, it is difficult to say whether they should be used or not because what they do is inform drivers if they are around police radar that are mobile or stationary, and that will make them take measure, either not to speed or if they are already speeding to bring down the speed. As a result the accepted use of the radar detecting equipment is to warn drivers about the speed they are making, while at the same time informing them if they are approaching the traffic radar guns that will give out ticket if they spot any vehicle speeding above the speed limit. However, the latest radar-detecting gadget can jam the police radar system so that it cannot read the speed the car is making.
The way the radar work is, the radar itself is simply made up of a radio and a receiver, and what it does is it uses an antenna to pick the electromagnetic waves it sends out when they bounce back and convert them into an electric current. The radar sends out a radio wave and if there is any object in front of the wave it will bounce back, and by calculating how long it takes the wave to come back, it is possible to calculate how far the object is.
Similarly, a radar can also calculate how fast a car is moving. Radio waves have what is known as frequency, the amount of oscillation in a given unit of time. Accordingly, when the radar gun sends out radio wave signals aimed at a standing target, the frequency of the echo will be similar, and it can only tell the distance when it bounces back with the same frequency. But when the target is moving it takes more time for the wave to reach the target and this will lower the frequency level because it stretches to reach a moving target, and by calculating the changes on the frequency level the radar has a mechanism to calculate the speed of the moving target. This is possible due to what is known as Doppler shift, which states that arriving at the speed a target is making is possible by looking at the shift a wavelength is making compared to a stationary object.
If the radar gun is handheld inside a moving police vehicle for example, the speed the police vehicle is making plus the difference the moving car is making will be the speed the car is making. If the police car is making 60 and if the radar detects the other car making 20, the speed the car is making is 80, passed the speed limit in some area.
The latest development in radar use is police have started using light, what is known as lidar gun, it stands for light detection and ranging, and this mechanism sends out of a burst of laser beams at a target and the light is reflected back after reaching the target. The speed it took the light to bounce back could be calculated because the speed of light is already known and that will be the speed the car is making, and this method is believed to be more accurate than the radio waves whose frequency change will have to be calculated to arrive at the speed the moving target is making.
The radar system had been working like this for many years now and both systems could be handheld or automated, and when the automated radar detects a speeding car it can activate a camera that will take the license plate of the car and the driver’s picture, and the speeder will end up receiving a ticket through the mail. That is where the detectors come into play by warning the driver that the traffic radar gun is around.
However, the latest development is the sophisticated radar detectors have the capability to jam a radar system so that it will get a wrong signal or it could be made not to see the license plate number or even the speeding car itself, because they can emit a light that will directly interfere with the laser beam the radar is sending out, making correct deciphering difficult, yet the law has not yet banned the device, except on commercial vehicles.
Both the police and the manufacturers are upping their sophistication regularly and when that happens, an expensive device can become obsolete requiring to be replaced by the latest device, which is a lucrative business for those who are involved in the manufacturing aspect of it.
As a result, one positive pretext used for using radar detecting device is that it could remind drivers in case they passed the speed limit, because when they get a signal of the existence of a police radar nearby, drivers will be reminded to watch the speed they are making. Other than that, even if they are not outlawed, they could also be used to evade being detected by a police radar, that could be moving in front of a car within a given distance or could be trailing a car from a given distance, even if it takes only seconds for the radar to detect the speed the car is making. The radar detectors could make speeding through a radar system easy at any speed by simply emitting a laser beam at the radar to make it confused and it could be done automatically.