This study evaluated reaction times to brake signals from standard incandescent brake lamps and from three alternative brake lamps with substantially faster rise times: neon, LED, and fast incandescent. The study, performed in a laboratory, simulated a daytime driving condition. The subject's task was to respond as quickly as possible to the onset of either of two brake lamps in the visual periphery, while engaged in a central tracking task. Brake signals were presented at two levels of luminous intensity. The results showed that reaction times to the alternative brake lamps were faster than to the standard incandescent lamp. The advantage averaged 166 ms for the LED and neon lamps (corresponding to a reduction of (corresponding to a reduction of 4.6 m in effective stopping distance from 100 km/hr), and 135 ms for the fast incandescent lamp (corresponding to a reduction of 3.8 m in effective stopping distance from 100 km/hr). (A)
Abstract