Comparison of alternative crash-avoidance sensor technologies

Sensor technologies of collision avoidance systems are identified based on a literature search about available products, prototypes, and experimental systems. These sensors constitute the front-end functional element of potential countermeasure systems to rear-end, backing, lane change, roadway departure, opposite direction, intersection, and reduced visibility crashes. The characteristics and capabilities of alternative sensor technologies are described based on published literature. Crash avoidance sensor technologies encompass microwave, millimeter- wave, and near-infrared radars; ultrasonic transducers, charge-coupled device cameras operating in near-infrared and visible bands; uncooled, passive far-infrared detectors; millimeter-wave imaging radar; and near-infrared communications.