Arizona Uses Motorists' Own Radar Detectors to Beef Up Safety

Arizona's Department of Public Safety (DPS) is testing an advanced warning system that uses transmitters and commercially available radar detectors to warn motorists coming upon accidents, stopped police vehicles or highway road crews on Arizona highways.

The state DPS has installed on a trial basis brick-size transmitters in 30 highway patrol cars. The transmitters are capable of sending more than 60 messages via K-band radio frequency (the frequency used by law enforcement) to motorists with radar detectors in their vehicles. Depending on the type of radar detector a motorist has, the detector will light up, beep, display a text message or use a synthetic voice to announce the upcoming hazard.

More than 6 million radar detectors in use in the U.S. are equipped with Safety Warning System (SWS) technology, enabling them to decode and display messages. Another 15 million that are not SWS-capable but still give a K-band warning will simply beep or light up to notify motorists of a potential hazard ahead.

"Any time you have a hazard on the roadway and motorist coming up to the hazard, it can cause problems," said Officer Bob Stein of the Arizona DPS. "This system gives you that much more warning." The transmitters have a range of about one-and-a-half miles, and messages can be quickly and easily changed from any laptop computer to accommodate changing road conditions.

"It extends the halo of lights and sirens on the roadway. It brings sound into the motorists' cars and wakes them up as to what's ahead," said Jason Richards, vice president of Safety Warning System L.C., Englewood, Fla. The system can be installed in range of vehicles -- police cars, fire and emergency vehicles, Department of Transportation work trucks, school buses and public works vehicles. Sensors in the transmitters allow the device to transmit different messages based on whether the vehicle is moving or stationary.

SWS transmitters are used in more than 30 states in police and other emergency vehicles, road construction and utility crew vehicles, and school buses. Arizona is the largest implementation to date for SWS. Indiana, where five state troopers over the past two years were struck and killed by passing highway motorists, is in discussions with SWS.

Richards warned that the system is not meant for large metropolitan cities where radar-detector use is lower. "The system really shines outside the cities -- on the interstates and in rural areas," he said.