Abstract
Many people die or become disabled because of motor vehicle accidents. Scientific data suggest that sleepy drivers or those driving at odd hours are more likely to make driving mistakes. Patients with obstructive sleep apnea and narcolepsy have been found to exhibit higher rates of falling asleep while driving. Treatment enhances the vigilance of these drivers. Tests measuring the extent of daytime sleepiness or drowsiness while driving can help identify at-risk drivers. There is a need to develop clear regulations governing periodic assessment of drivers' risks of falling asleep at the wheel, especially commercial drivers.