ABSTRACT
Driving when drowsy is a well-known risk factor for motor vehicle accidents (MVAs) with associated serious injuries and fatalities. The problem is common, as demonstrated by numerous studies in Europe and theUnited States. Up to 60% of drivers admit to feeling sleepy when driving. Forty percent of people in surveys admit to having nodded off or briefly fallen asleep when driving in the previous year. This is a more common in teenage drivers-with up to 70% admitting drowsiness while driving in the previous year. Approximately 15% of fatalities due to MVA are associated with a drowsy driving. This is particularly common in ages 15 to 35 years. Half of fatalities in commercial truck (or heavy goods vehicle)-related MVAs reported in the United States are associated with drowsiness. The aim of this guidance is to remind clinicians of the effects of drowsiness while driving and the groups at highest risk of this and to provide a framework for evaluating such patients and how to prevent or reduce the risks. Finally, this chapter provides clarity about what information should be provided to patients, based upon the requirements of regulatory driving licensing authorities.
Drowsiness affects neurocognitive function relevant to driving skills. These include attributes of attention, alertness, reaction times, and executive functions of working memory, processing, and judgment.
