Crash risk can be assessed based on miles driven, and on number of license holders or number of members of a particular group. The most likely reasons for the overinvolvement of youthful drivers in accidents are immaturity and lack of driving experience. The immaturity associated with youth is manifested in risky driving behaviors including speeding, following too closely, accelerating too rapidly, and in general, driving aggressively. Various studies have found a correlation between certain personality traits in young drivers (rebelliousness, risk taking, independence, and defiance of authority), deviant driving practices, and accidents and driving violations. Accident involvement has also been found to be related to drug and alcohol use and other delinquent behaviors. The most successful ways to reduce accident likelihood are to manipulate age requirements for driving and driving experience through laws and regulations. 3 figures and 34 references