IS RADAR RELIABLE

Most of the queries and complaints directed to the American Automobile Association Potomac Division concern the use of radar by law enforcement officials. Police have been using radar (radio/detecting/ranging) to detect speeders for about 30 years, and the National Highway Traffic Safety Administration supports the use of radar as an effective speed limit enforcement tool. Radar units emit a high frequency radio beam that bounces off a moving object and is reflected back with a changed frequency. This is translated into miles per hour by the radar set. Stationary radar sets, such as radar guns, are almost infallible because they are relatively simple and are used in a highly controlled environment. Moving sets are more complex and subject to variables due to motion. These devices determine an object's velocity based on the patrol car's speed while closing with a target vehicle. Because moving radar has difficulty isolating a specific car within a moving mass of traffic, radar must be used as a sophisticated gauge to back up a visual observation. Although false radar readings are possible, they can be prevented by proper use of the equipment. Proper training for radar operators and calibration of radar units for accuracy are essential. Separate notes report that some motorists use radar detectors, illegal in some jurisdictions, and that fighting a radar violation is difficult, although a good driving record may result in a lighter penalty.