Rear Lamp Reaction Time Study-Comparison of Incandescent Bulbs and LEDs 2002-01-0379

The paper deals with the current progress in rear lighting technology. In developing the best vehicle in terms of traffic and driver safety, a rear signal light becomes increasingly important. Many car manufacturers are offering an LED CHMSL (Center High Mounted Stop Lamp) as one mean of increasing traffic safety. This investigation is based on the comparison of reaction times between lighting devices equipped with conventional incandescent bulbs and those equipped with LEDs. In combination with the CHMSLs, LED signal lamps provide value in styling and safety features. Laboratory measurements had already been done resulting in shorter reaction times with LEDs. This study discusses experimental analysis of driver reaction times in response to the stop function of rear lamps including CHMSLs. These reaction times were noted in various combinations of real traffic conditions, using different combinations of conventional tungsten incandescent bulbs and LEDs as light sources, and in static conditions as well as in dynamic (driving) conditions. For those tests two sets of RCL (rear combination lamps) were prepared - with bulbs and LEDs and also two sets of CHMSL - bulbs and LEDs. Reaction times of drivers were measured responding to these signals. The results will be discussed in detail.