Barbiturates are general nervous system depressants which are commonly used as sedatives and hypnotics. Approximately 4% of the adult population, 12% of high school students and 19% of college students have reported using barbiturates. The lack of controlled studies comparing barbiturate involvement in traffic accidents and in the at-risk population has restricted any conclusive interpretations which can be made about the causal relationship between barbiturates and traffic accidents. Barbiturate incidence in traffic accident involvement varies from 2 to 9%. The variance in numbers represents different methods in data collection, different techniques in identifying barbiturates in body fluids and the differences in the populations sampled. Laboratory studies have found barbiturates at moderate doses to degrade driving skills. Motor skills performance, perceptual and tracking task performance and vehicle-handling test performance are impaired under barbiturates. This impairment is further degraded by the combined use of alcohol and barbiturates beyond that found under either drug alone. It is clear that barbiturates are dangerous for driving and its effects are likely to produce impairment on those components of driving necessary for safe operation of a motor vehicle.