Should motorcycles be operated within the legal alcohol limits for automobiles

A motorcycle simulator was used to assess operating performance of 14 experienced motorcyclists with varying breath alcohol concentrations. Riding error scores in three defensive and evasive maneuvers plus distance traveled in a standard time period were documented at baseline and at predetermined intervals following controlled alcohol consumption. The results revealed a positive correlation between total errors and breath alcohol concentrations within a range well below the commonly accepted legal limit of intoxication of 0.10 mg/dL. There was a highly significant increase (p < 0.0055) in an operator's tendency to leave the roadway (an error that is frequently fatal for motorcyclists), as well as a reduction in ability to complete a timed course. Moreover, performance errors increased while operators were "sobering up," a dramatic finding not heretofore established in previous studies. Since the present definition of the legal limit of intoxication for motorcyclists is based on automobile studies, noted increases in reaction time and performance errors support the hypothesis that "legal alcohol levels" should be lowered for motorcycle operators.