In 1989 motor vehicle accidents were the second largest single cause of death in persons aged 15 to 24 years in the United States (U.S. Department of Commerce 1992). Sleepiness is increasingly recognized as a causal factor in crashes and may be a particular risk in chronically sleep-deprived young people (Carskadon, 1990, 1993). For example, data from a series of 4,333 automobile crashes attributed to the driver's falling asleep (but not being intoxicated) in North Carolina from 1990 through 1992 demonstrated that the peak age of the driver in such crashes was 20 years (Pack, Pack, Rodgman, Cucchiara, Dinges, & Schwab, 1995). Furthermore, 55% of the sleep-related crashes involved a driver younger than 25 years old. This disproportionate age distribution of fall-asleep crashes singles out young people as a singularly high-risk group.

We have learned much about the sleep processes and sleep pattern development of adolescents over the past 20 years, enough to be confident in saying that many high school and college-aged young people do not obtain adequate sleep to maintain full alertness. High school students, in particular, go to bed late, wake up early, and sleep on average about 7 hours and 15 minutes a night (Wolfson & Carskadon, 1998). On the other hand, we have good evidence that adolescents probably need at least 9 hours to 9 hours and 15 minutes of sleep a night to maintain optimal alertness (Carskadon, Orav, & Dement, 1983).