Test Road Experiment on Imminent Warning Rear Lighting and Signaling

Abstract

Objective: This paper describes an experiment directed toward refinement and initial field testing of two potential countermeasures for the problem of rear-end (RE) crashes. The countermeasures consist of “imminent warning” signals intended to direct the following driver's visual glance to the lead vehicle as it brakes rapidly to a stop and for a short time thereafter. Background: RE crashes are the most frequently occurring type of light vehicle crash, making up at least 25% of all crashes. Method: A preliminary experiment was conducted to facilitate improvement of the attention-getting capability of an alternating pair of lamps. In the main experiment, an oscillating narrow beam lamp (a promising candidate from a previous experiment) and an improved alternating pair (improved as compared with that in a previous experiment) were compared with ordinary rear lighting. Seventy-two drivers were purposely distracted by in-vehicle tasks as the lead (surrogate) vehicle braked hard. Results: Results showed improvements of 0.25 to 0.35 s in brake activation times for the two enhanced configurations as compared with ordinary rear lighting. Conclusion: The two enhanced lighting configurations show promise in reducing the number and severity of RE crashes. Application: The methods and results of this study can be applied to the future design and evaluation of automotive rear-end lighting designed to reduce RE crashes.