Young novice drivers are at significant risk on the road because they lack both the judgment that comes with maturity and the skill that comes with experience.

Although adolescence is the healthiest period of the life span physically, a time when young people are close to their peak in strength, reaction time, immune function, and other health assets, their overall morbidity and mortality rates increase 200 percent from childhood to late adolescence. Many of the primary causes of death and disability in these years—which include crashes, suicide, substance abuse, and other risky behaviors—are related to problems with control of behavior and emotion.
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This period is characterized by increased emotional intensity and changes in romantic motivation. It is associated with increases in risk-taking, novelty-seeking, and sensation-seeking, as well as an increased focus on social status. These attributes can have significanteffects on driving behavior. Moreover, cognitive development occurs on an unrelated trajectory that is not complete until the early 20s—long after puberty is over. Thus, the capacity for planning, logical reasoning, and understanding the long-term consequences of behavior are far from fully developed during the period when most young people in America are beginning to drive.

A leading cause of motor vehicle injuries appears to be human error (Bever, 1996). A variety of reasons are given for young adults' overrepresentation in motor vehicle crashes (Begg & Langley Langley, 2001). Research indicates contributing factors include inexperience, inattention, poor risk perception, impulsivity, and a propensity for thrill-seeking, and sensation-seeking (Jonah, 1986). Other contributors involve risky driving behaviors such as driving at excessive speed, dangerous overtaking, close following, driving after drinking, or driving after using drugs (Williams, 1998).

Teens are especially vulnerable to the risks of drinking and driving. Younger, newly licensed drivers, as a group, have comparatively few alcohol-related crashes, while older, more experienced teen and young adult drivers have more such crashes than do adults. Nevertheless, alcohol significantly impairs driving capacity among all teenagers—and at lower blood levels than typically affect adults. As Figure 2-2 shows, the risk of crashing rises dramatically with blood alcohol content (BAC) at any age, and the effects are more marked for drivers ages 16 to 20 than for those ages 35 to 49. While peaks in substance use typically occur slightly later in the teen years (around ages 18 to 20) than driving usually begins, younger teens certainly use alcohol. Moreover, some evidence suggests that adolescents’ physiological responses to alcohol may be different from those of adults, and specifically that teens may be less sensitive to signals that they are impaired (National Research Council and Institute of Medicine, 2004, 2006).