light-truck operators. Despite the relevance of alcohol to motorcycle safety, only limited information on the impairing effects of alcohol on motorcycle operator performance is available. To address this issue, NHTSA sponsored a research study to assess the impairing effects of alcohol (up to the current per se limit of .08 g/dL), on rider performance involving a broad set of basic motorcycle riding skills.
These riding skills were assessed on a test track with task scenarios based on the Motorcycle Safety Foundations (MSF) training program. This study used a balanced incomplete block design to remove confounding artifacts (learning effects) by randomizing four BAC levels across three test days. Performance was characterized in terms of riding strategy used to cope with the effects of alcohol as a neurological stressor and the amount of resulting impairment with reference to specified performance standards. The analysis controlled for rider gender and age, riding skill, and drinking history.
Motorcycle fatalities have increased for the ninth consecutive year and now represent 11.3 percent of all traffic fatalities in the U.S. One factor that continues to be associated with motorcycle fatalities is alcohol. In 2005, twenty-seven percent of motorcycle operators had blood alcohol concentrations of .08 g/dL or higher versus 22 percent for passenger car operators, and 21 percent for
