Revised estimates of the U.S. drowsy driver crash problem size based on general estimates system case reviews.

A revised estimate of the incidence of crashes involving driver drowsiness/fatigue is provided based on analysis of General Estimates System (GES) data and a review of 562 GES cases from 1993. Cases selected for review had coded characteristrics suggesting a "Drift-Out-Of-Lane" scenario but were not cited as drowsines-related in GES. The case review indentified some "definite", "probable", and "possible" drowsy driver crashes not captured by the normal GES data coding process. It indicated that drowsiness/fatigue is a discernible causal factor in 1.2 to 1.6% of Police Accident Reports, as compared to the baseline GES estimate of 0.9%. (A)