Unlike conventional "down-the-road" radar speed-measuring devices, across-the-road radar systems do not require an operator and can be programmed to detect and record vehicles traveling above a predetermined speed. In addition, these devices can be set to look selectively for cars, motorcycles or trucks. The newer systems are also less likely to be detected by speeders because the radar beam used is pointed across, rather than along the road.
The National Highway Traffic Safety Administration (NHTSA) has adopted the new across-the-road radar standard along with two other updated NIST standards for down the road radar and for lidar, a speed enforcement technology that uses laser pulses rather than radio waves.
All three standards define minimum performance specifications and measurement procedures for verifying these requirements so that motorists, courts and law enforcement can be assured that these systems will perform as expected.
The standards also have been adopted by the International Association of Chiefs of Police (IACP), which currently funds the NIST work. NHTSA and IACP work with NIST to establish and update standards for speed-enforcement technology to ensure the systems used by law enforcement are reliable.
IACP publishes a list of those speed-enforcement devices that meet the NIST-developed standards. NHTSA offers law enforcement agencies grants to purchase new speed-enforcement systems included on the IACP list.