A field study was conducted to evaluate an advance brake warning (ABW) light activation system. The ABW system detects very rapid accelerator pedal releases and activates the brake light. If the driver brakes within 1.0 s, then continuation of the brake light is governed by the brake pedal. Otherwise, the light goes off. The ABW system was installed on six vehicles driven by their regular users, who were unaware of the system or the study. A total of 61,668 km were driven, in which the drivers braked 95,394 times. The ABW system was activated on 820 of those occasions, providing the following driver a 0.22 s warning. It was determined that the emergency braking activating the ABW system is relatively rare, occurring on average 13.3 times per 1,000 km and less than 1 percent of all brake actions. False alarms occurred in 23 percent of all ABW activations but were insignificant relative to the total number of brief braking actions lasting less than 1.0 s. It therefore appears that the advance brake warning light can provide the intended information without being a safety hazard to following drivers.
Abstract