On the Back of the Bus

With rear-end collisions being the most common crash experienced by transit buses and with the country's estimated 45,000 transit buses suffering a crash about once a year, this research focused on a device to reduce rear-end collisions. The subject of this report is a light bar, comprised of eight separate units, that sits on the rear of the bus at about eye-level to a driver and would be intended to warn the driver of the need to stop. It is intended to ultimately be used in conjunction with a detection system on the rear of the bus that would cause the warning to go off when it sensed an impending collision. Replacing incandescent bulbs with LEDs reduces the time needed for the bar to light significantly. The next task was to determine the pattern for igniting the eight units that drivers would perceive most rapidly. Tests indicated that turning on the units sequentially enabled observers to see them significantly sooner, enough to provide an extra 4.4 feet of stopping room on average for a car traveling at 30 mph.