Abstract
The flash lights and send help (FLASH) system described in this article uses an electro-optical detector designed to enable passing drivers to conveniently summon assistance for motorists in distress. The driver signals at designated reporting stations by flashing his high-beam lights three times, after which a roadside unit detects the head lamp flashes and transmits an identifying tone signal to a central monitoring station, whose operator dispatches a service vehicle to the section of the road under that detector's jurisdiction. The detector performs reliably over a range of 1000 feet during daylight or darkness, and the concept, design and other details of the system is discussed in relation to the practical operational requirements.