Radar detectors are popular items among today's drivers. Radar guns and similar devices are used by police to measure speed by bouncing radio waves off of the vehicles. A radar detector is used to alert a driver when police radar is being used. The radar detector is activated when it detects the radio wave, providing the driver with notice that his or her speed is being monitored. Radar detectors are legal in 49 states, banned only in Virginia and Washington, DC. However, there are concerns about the safety of radar detectors as well as the tendency of drivers to use them as a license to speed.
Radar vs. LIDAR
Radar is the traditional means that police use to measure speed. However, technological advances have led to the development of LIDAR. LIDAR, or Light Detection and Ranging, uses beams of laser light in place of the radio signals used by radar. LIDAR is considered more accurate than radar, as it can target a specific vehicle at a range of 3000 feet. The beam is also smaller and more directed than that of a radar gun.
Most modern radar detectors also detect LIDAR signals. However, LIDAR detection is not nearly as reliable as radar detection. The smaller size of the beam makes it less likely that the detector will receive the beam.
Nonetheless, relatively few police departments use LIDAR. The technology is significantly more expensive than comparable radar technology. LIDAR also cannot be used while the police vehicle is in motion. As LIDAR technology becomes more refined and prices drop, it is being put into service to replace aging radar units.
Radar Detector Detectors
Radar detector detectors are often used in jurisdictions that have outlawed radar detectors. Radar detectors are based on small oscillators that emit a slight signal. Radar detector detectors pick up on this slight emission. However, radar detector manufacturers have fought back with so-called "stealth" radar detectors. Early stealth detectors contained radar detector detector detector technology that shut down the detector when a detector detector was noted. Today, most radar detectors operate at a frequency that is outside the range of older detector detector units. However, a new radar detector detector called the Spectre III is able to detect almost every radar detector currently on the American market.
Some safety advocates are concerned that radar detectors may encourage drivers to speed. Some research refutes this. In a study by Yankelovich Clancy Shulman, radar detector users were found to drive an average of 60,000 miles more between accidents than non-users.
Radar Detector Laws
In the United States, only Virginia and Washington, DC have banned radar detectors in passenger vehicles. Radar detectors are also banned on US military bases. Connecticut had a law against radar detectors, but that law was repealed in 1998. Department of Transportation restrictions effectively ban radar detectors in commercial vehicles.
In Minnesota and California, it is illegal to hang any object from the windshield through the use of suction cups. However, visor-mounted and dashboard-mounted radar detectors are legal.
In Illinois and New York, radar detectors are specifically banned in commercial vehicles over 10,000 pounds in weight, and in all vehicles weighing more than 18,000 pounds.