Examining Large-Truck Crash Risks Attributed to Driver Fatigue and Hours of Sleep

Driver fatigue is an important risk factor for large truck crashes. Although the positive influence of driver fatigue on increased crash risks is consistently identified in most studies, the methods for examining driver fatigue vary by studies and the estimated proportion of truck crashes involving fatigue also vary. Two general methods have been used to identify the presence of driver fatigue in crashes. The first approach is by the expert opinions of the investigating officers using information from interviews with the drivers or other forensic evidence to determine if a driver was fatigue. The second approach relates the presence of fatigue to the drivers’ hours of works and/or hours of sleep prior to the crashes. Using the Large Truck Crash Causation Study (LTCCS) data, this study examined how different fatigue-related driver factors correlate with different types of crashes. Specifically, LTCCS variables assessing driver fatigue and hours of sleep are examined. The results of the analysis show that driver fatigue is more prominent in single truck crashes than in multiple truck crashes. 28% of the single truck drivers were identified as fatigued, but only 0.8% of the drivers involving in the first two trucks of multiple vehicle crashes were fatigued. In addition, many LTCCS variables related to driver fatigue such as inattention and distraction do not appear to be significant in most cases. It is noted that the values for many of variables intended to assess driver fatigue were subjective assessment derived from interviews or other subjective sources. The study found that the hours of sleep at the last sleep interval is a critical factor affecting the risk associated with committing driver errors leading to crashes. It is found that, among the drivers involving in crashes with more than 6 hours of sleep, a national estimate of 45% of them ended up in the crashes due to various driver behavioral factors. For those involving in crashes with less than or equal to 6 hours of sleep, 80% of them involved in the crashes due to critical driver performance errors. The result can be interpreted as that sleeping for more than 6 hours at the last sleep interval before driving can reduce the crash risk due to driver performance errors by 35%.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; References; Tables;
  • Pagination: 25p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01151206
  • Record Type: Publication
  • Report/Paper Numbers: 10-4008
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 12:03PM