This scientific poster presents a study in which 204 motorway crashes resulting in 242 fatalities were analyzed. These fatalities represented all fatal accidents in the state of Bavaria in 1991 (20% of all motorway-fatalities in Germany). Causative factors were evaluated and discussed in an interdisciplinary working group, which include experts in psychology and sleep research with a special focus on crashes where drowsiness was a factor. Reduced vigilance (falling asleep and inattentiveness) was a factor in 35% of the crashes studied. Monotony, long-driving duration and daytime drowsiness in older drivers characterize this group. The analysis of the time of day distribution shows that drivers aged 45 years and older had vigilance problems during daylight hours peaking in the afternoon, whereas younger drivers were responsible mostly for nighttime crashes peaking in early morning hours. These findings correlate with experimental sleep studies. Human error (misjudgement) was estimated to be a factor in 46% of the crashes. Another important finding was that, even with a seat belt wearing rate of 95% in the front seats in Germany, only 5% of the non-belted car occupants were responsible for 35% of the fatalities. Because falling asleep and inattentiveness were unexpected prominent crash causation factors, roadway interventions such as rumble strips, driver vigilance control systems and more public information campaigns should be adopted. (A)
Abstract