If you are one of those drivers who believe that the posted speed limits are too low, then you might well have a radar detector attached high up on the windshield of your car. Or, if you just have a habit of keeping your foot on the gas pedal, you might well have a radar detector too.
Whatever the case, a radar detector basically does what its name implies, it "detects radar." Radar detectors are electronic devices that allow drivers to be alerted to police officers who are checking the speeds of vehicles over a mile ahead in the roadway.
Police officers have been using radar for more than thirty years now as a way to monitor the speeds of cars. It is estimated that more than one hundred thousand speed radar units are used today by the police officers in the United States. Many of the conventional radars have now been replaced with laser speed radars.
These use an advance in a technology known as infrared light instead of radio waves. The laser speed radars are much harder to sniff out because the laser beam does not give off signals. Laser speed radars also work on an "instant - on", so they can target a car and the driver will get a little warning from his or her radar detector.
A radar detector can cost you upwards of a hundred dollars or more, but it can actually help to save you from getting a speeding ticket, as well as a fine, plus points on your driver's license, and higher car insurance rates.
In light of what it can save you, the price doesn't seem so high after all. For these reasons, many drivers across the country, especially long-distance travelers, rely on a radar detector to help keep them from being caught speeding.
In order to understand how a radar detector works, you must first understand how a speed radar can catch you when you are speeding down the road. Basically, a speed radar is a radio transmitter and a radio receiver all in one. It is used to measure the speed of anything that is traveling or moving. The conventional radars measure the speed by sending out radio waves and waiting for the reflection of the waves from the moving car.
It can then compute how fast the car is moving. This is known as the "Doppler Shift." The laser speed radars work in basically the same way, except that they send out a beam of infrared light that reflects back from the moving car. The laser speed radar is more effective in that it can be aimed at a specific car. It is also much more accurate in measuring speed than its older counterpart.
So, a radar detector works by actually detecting these frequencies. A detector is tuned in to detect the specific frequencies that are used by the speed radars of the police officers. The best radar detectors meet unwanted "electronic contamination" such as automatic door openers, burglar alarms, and Cetera.
State laws change all the time, but the use of radar detectors in cars and light trucks is legal in every union state except Verdunia and Washington DC. Radar detectors are illegal in all trucks that weigh in excess of ten thousand pounds due to a regulation issued by the Federal Highway Administration.
Radar detectors are also legal in some parts of Canada. They are currently illegal in Manitoba, New Brunswick; Newfoundland, Ontario, Prince Edward Island, and Quebec. If you are traveling through a state or a Canadian province that does not allow the use of radar detectors, it would be a good idea to disconnect yours if you have one, or at least shut it off until you cross over the state line into a state or province where they are legal.