A review of the scientific literature regarding the effects of alcohol on driving-related skills was conducted. The review covered 112 articles dated from 1981 to 1997. Results were indexed by blood alcohol concentration (BAC) and behavioural area and entered into a database. Two separate analyses were conducted. The first analysis determined the lowest BAC at which impairment is reliably present in driving-related skills. The second analysis determined the thresholds of impairment for each of 12 separate behavioural areas. It was concluded that: (A) Alcohol impairs some driving skills beginning with any significant departure from zero BAC. By BACs of 0.05 g/dl, the majority of the experimental studies examined reported significant impairment. By 0.08 g/dl, more than 94% of the reviewed studies showed impairment in the skills they measured. (B) Specific performance skills are differentially affected by alcohol. Some skills are significantly impaired by BACs of 0.01 g/dl, while others do not show impairment until BACs of 0.06 g/dl. (C) Discrepancies among the reported BAC thresholds of impairment within a behavioural area reflected a lack of standardisation of testing methods, instruments, and measures in the studies reviewed. (D) All drivers can be expected to experience impairment in some driving-related skills by 0.08 g/dl or less. (A)
Abstract