Drowsy Drivers: Effect of Light and Circadian Rhythm on Crash Occurrence

Fatigue is recognized as a pervasive problem for drivers, with effects judged comparable to those of alcohol. Unlike alcohol, which has a clear legal limit for impairment, there is no functional, objective measure of fatigue to identify drowsy drivers, although it is associated with Circadian rhythm. Severe single vehicle crashes, from the crash reports maintained in Ontario for 1999-2004 were analyzed. Crashes occurring when light varies but Circadian rhythms are low (2-5 am and 2-4 pm) were compared with crashes occurring when light conditions are similar but Circadian rhythm are higher (9-11 pm and 10 am - 12 noon). Logistic regression was used to see how light and other factors would predict single vehicle crashes occurring at times of low Circadian rhythm, when fatigue is more likely. Initial results indicated many circumstances associated with occurrence at these times: the age and sex of the driver and reported driver condition as well as weather. Some of these effects may be partly explained by exposure; e.g., young men may be more likely to drive in the early morning than women or older drivers. There is, however, an interaction between light and presumed alertness. In separate analyses for daytime and night time crashes most variables were significant for nighttime crashes but not for daytime events. The effects of alcohol and youth remained. Light, or its lack, may exacerbate the effects of other factors; this can be further investigated in controlled environments such as sleep laboratories and/or driving simulators.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Jin, Yue
  • Chipman, Mary L
• Conference:
  • Transportation Research Board 87th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2008-1-13 to 2008-1-17
• Date: 2008

Language

• English

Media Info

• Media Type: DVD
• Features: References; Tables;
• Pagination: 15p
• Monograph Title: TRB 87th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Age groups; Alcohol use; Automobile drivers; Circadian rhythms; Drunk driving; Fatigue (Physiological condition); Gender; Highway safety; Periods of the day; Safety; Time of crashes
• Geographic Terms: Ontario (Canada)
• Subject Areas: Highways; Safety and Human Factors; Society; I83: Accidents and the Human Factor;

Filing Info

• Accession Number: 01100668
• Record Type: Publication
• Report/Paper Numbers: 08-1231
• Files: TRIS, TRB
• Created Date: Jun 3 2008 7:32AM