Enhanced Rear Lighting and Signaling Systems Project Final Report Emphasizing Task 3 Results: Test Road Experiment on Imminent-Warning Rear Lighting and Signaling

Task 3 of the Enhanced Rear Lighting and Signaling project was directed toward refinement and initial field testing of two “imminent-warning” signals. These signals are intended to direct the following driver’s visual glance to the lead vehicle as it brakes rapidly to a stop. The signals can also be used to warn of an impending rear-end crash. Task 3 consisted of a preliminary experiment and a main experiment. In the preliminary experiment, modifications to an alternating pair of lamps were tested in a static situation using human-factors experts. Results of the experiment indicated that use of greater drive voltage and kick voltage improved the attention-getting capability of the alternating pair. Results also showed that an alternating frequency of 4.0 Hz was optimal. Previously, the TCL (traffic clearing lamp) had been selected as the most promising imminent-warning signal. Consequently, in the main experiment, the TCL and the IAP (improved alternating pair) were compared to ordinary rear lighting. The main experiment was conducted on the Virginia Smart Road in Blacksburg, Virginia, using a surrogate vehicle (drawn by a lead vehicle) containing conventional lighting and the two new, imminent-warning lighting configurations. Seventy-two ordinary drivers, split into three groups, participated. Driver subjects were purposely distracted by in-vehicle tasks as the lead (surrogate) vehicle underwent hard braking. Responses were compared for the conventional and two enhanced lighting groups. Results showed improvements in brake activation times of 0.25 to 0.35 seconds, corresponding to 15 to 30 feet (4.6 to 9.1 m) of additional stopping distance for the enhanced lighting. The TCL was just slightly better than the IAP. The results also demonstrate a learning effect between the first and second exposures, with braking performance improving with second exposure. Other measures suggested the eyes are drawn to the forward view more quickly with the enhanced lighting. This report fully describes the experiments and results. It then recommends additional refinements and fleet testing because of the promise shown by the results thus far.

• Record URL:
  • http://www.nhtsa.gov/DOT/NHTSA/NRD/Multimedia/PDFs/Crash%20Avoidance/2005/Task_3_Results.pdf
• 
• Corporate Authors:

  Virginia Polytechnic Institute and State University, Blacksburg

  Virginia Tech Transportation Institute
  3500 Transportation Research Plaza
  Blacksburg, VA  United States  24061

  National Highway Traffic Safety Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Wierwille, Walter W
  • Lee, Suzanne E
  • DeHart, Maryanne C
• Publication Date: 2005-3

Language

• English

Media Info

• Media Type: Web
• Edition: Task 3 Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 174p

Subject/Index Terms

• TRT Terms: Brake lamps; Braking; Crash avoidance systems; Field tests; Reaction time; Rear lighting
• Uncontrolled Terms: Crash-imminent warning
• Subject Areas: Highways; Safety and Human Factors; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 01095910
• Record Type: Publication
• Report/Paper Numbers: HS-809 864
• Files: HSL, TRIS, USDOT
• Created Date: May 2 2008 4:15PM