Evaluation of automotive stop lamps using incandescent and sweeping neon and LED light sources

This paper describes a study of visual responses to center high mounted stop lamps (CHMSLs) using a newly developed sweeping neon lamp. This study compares sweeping neon, incandescent, and light-emitting diode (LED) technologies. The incandescent CHMSL was a conventional after-market CHMSL brake light. The sweeping neon CHMSL used a novel controller whereby the luminous signal started at the center of the neon tube and grew in a "sweeping" motion outward toward the ends of the tube at an adjustable rate. The sweeping LED CHMSL had a segmented display simulating the sweeping characteristics of the neon CHMSL. Both the neon and LED CHMSLs had faster onset times than the incandescent CHMSL. Experimental subjects performed a tracking task cognitively similar to driving, and released a flip switch upon detecting the onset of the CHMSLs, which were mounted so as to be seen peripherally. Reaction times and missed signals for incandescent and for sweeping neon and LED CHMSLs are presented for simulated daytime driving conditions. Such data permit comparisons among CHMSL technologies to examine if sweeping neon technology result in any visual benefits, and to optimize signal characteristics for minimizing reaction time and the likelihood of missed signals.