Millimeter wave safety warning system for in-vehicle signing

Georgia Tech Research Institute (GTRI) has developed a millimeter wave safety warning system for in-vehicle signing for use in the nation's Intelligent Transportation System (ITS, formerly IVHS). The Safety Warning System TU (SWS) utilizes a homodyne radar that operates at 24.1 GHz as both a radar and a system to transmit highway safety messages. The warning message is received by a police radar detector or stand-alone safety warning receiver without radar detector capability. When the message is received, it is displayed to the driver via an alphanumeric light emitting diode (LED) display. The message can also be announced by a voice synthesizer internal to the receiver or by a flashing LED labeled "SWS." The system is designed to inform the driver that he or she is being overtaken by a police car or emergency vehicle in motion. When the police car or emergency vehicle stops, the radar transmitter senses that the platform is no longer moving and the system automatically changes its message to warn approaching drivers of a stationary hazard ahead. A second safety warning transmitter deployment concept is to mount the unit near the highway at a fixed location. The fixed location SWS is designed to be programmable and transmit any one of 64 fixed text messages.