Evaluation of driver drowsiness by trained raters.

Drowsiness of vehicle operators is a major hazard in transportation systems, and methods need to be developed for practical evaluation of drowsiness level. One suggested approach is observer rating. Accordingly, an experiment was carried out using trained observer-raters to evaluate the levels of drowsiness of drivers, the drivers' faces were recorded on videotape. Videotaped segments of drivers at various stages of drowsiness were presented in two sessions separated by a time interval of one week. The experiment was directed at determining test-retest reliability, interrater reliability, intrarater reliability, and consistency. Results indicate that such ratings are reliable and consistent. A subsequent experiment shows that ratings covary with other known indicators of drowsiness.

Development of models for on-board detection of driver impairment.

Two of the leading causes of automobile accidents are driver impairment due to alcohol and drowsiness. Apparently, a relatively large percentage of these accidents occur because drivers are unaware of the degree to which they are impaired. The purpose of this research was to develop models, utilizing changes in driver behavior, which could detect driver impairment due to alcohol, drowsiness, or the combination of alcohol and drowsiness, and which could be practically implemented in an automobile. A computer-controlled automobile simulator was used to simulate a nighttime highway driving scenario for six drivers who participated in each of four conditions: a control condition, an alcohol condition, a sleep-deprived condition, and a combined alcohol and sleep-deprived condition. The results indicated that a useful on-board drowsiness detection device is possible and practical for highway driving. The results also showed that on-board alcohol impairment detection may be possible at levels below the legal driving limit in most states (BAC 0.1%).