DAYTIME RUNNING-LIGHTS PROJECT IV: TWO-LANE PASSING PERFORMANCE AS A FUNCTION OF HEADLIGHT INTENSITY AND AMBIENT ILLUMINATION

The experiment investigated the ability of subject drivers to perform a two-lane passing task, with oncoming traffic, as a function of the level of ambient illumination and the headlight intensity of the oncoming vehicle. Eight experienced drivers performed both passing trials and gap-estimation trials, under closed-course conditions, during dawn and dusk hours. Levels of ambient illumination varied from approximately 0.02 to 200 ft-c during the experiments. Headlight conditions included no lihgts, normal low-beam headlights and low-beams with filters which reduced their intensity to about 1/3 of normal. Results indicated that the gaps accepted by drivers in a two-lane passing situation increased with an increase in the intensity of the headlight of the oncoming vehilce. The range of gaps accepted across headlight conditions was less, however, at higher levels of ambient illumination than at lower levels. Best results in terms of mean gaps accepted and minimum variability in performance was achieved with the reduced intensity low-beams. Results are discussed in terms of the optimum intensities of daytime running-lights. Suggestion for future research are presented. /Author/

• Supplemental Notes:
  • SRIS 760182 in Part II under the title-Vehicle Detection as a function of Headlight use and Ambient Illumination.
• Corporate Authors:

  Ministry of Transport, Canada

  Tower C, Place de Ville
  Ottawa, ONo K1A 0N5,   Canada 
• Authors:
  • ATTWOOD, D A
• Publication Date: 1976-2

Media Info

• Features: Figures; References; Tables;
• Pagination: 49 p.

Subject/Index Terms

• TRT Terms: Driver performance; Drivers; Gap acceptance; Headlamps; Low beamed headlamps; Passing; Personnel performance; Vehicle lighting
• Old TRIS Terms: Low beamed headlights; Running lights
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00142021
• Record Type: Publication
• Source Agency: National Safety Council Safety Research Info Serv
• Report/Paper Numbers: TR-RSU-76/11 Final Rpt., HS-019 176
• Files: TRIS
• Created Date: May 31 1989 12:00AM