In the United States in 2004, 16-year-old drivers were involved in 957 fatal crashes that killed 1,111 people. Sixteen-year-old drivers have an especially high risk of crash involvement. Per mile driven, their crash rate is almost 10 times the rate for drivers age 30 to 59 and more than twice the rate of 18- to 19-year-old drivers.1 Graduated Driver Licensing (GDL) is one increasingly popular approach to managing the serious problem of high rates of fatal and nonfatal crashes among beginning drivers.
GDL allows beginning drivers to build experience incrementally before they are exposed to more hazardous driving situations. It achieves this by increasing licensing age, requiring more supervision in the initial phases of driving, and reducing exposure to high-risk situations such as carrying teen passengers and nighttime driving. The first phase of GDL is a learner’s period with supervised training. This is followed by an intermediate period where unsupervised driving is limited to less hazardous situations and a final stage without restrictions. By the end of 2004, 41 States and the District of Columbia had instituted some form of GDL that included an intermediate stage.
Prior evaluation studies of GDL programs comparing rates before and after GDL implementation in individual States have reported reductions in fatal crash rates of novice drivers that ranged from 11 percent to 32 percent.2-10 More recently, Dee et al.11 reported a 6-percent reduction nationally in crash fatalities of 15- to 17-year-olds associated with GDL programs. The greatest reductions (19%) were in States with programs ranked “good” by the Insurance Institute for Highway Safety using a system based on the presence and strength of components considered as desirable.11 12 However, the type of analysis used by Dee et al. does not make it possible to compare programs with different combinations of program components. Other prior evaluations have not taken advantage of the unique environment of the United States that makes it possible to compare programs among States, with attention to their specific components.
State GDL programs differ with respect to which components are included and in the specific requirements of each component, such as the required number of hours of supervised driving. However, evaluation of the individual components of GDL separately is not possible because in most States several components have been introduced or changed simultaneously, and their effects cannot be separated. Although a study of the effectiveness of individual GDL components was not possible, it is still possible to determine empirically which types of GDL programs are associated with the lowest fatal crash involvement rates for16-year-old drivers.
A nationwide study was therefore undertaken to assess the overall impact of GDL programs on fatal crashes of 16-year-old drivers, and to determine what types of GDL programs are associated with lower fatal crash involvement rates for 16-year old drivers.
The research, based on 43 of the 48 contiguous States and using data for 1994 through 2004, analyzed changes in fatal crash involvement rates of 16-year-old drivers in relation to the characteristics of the various GDL programs, which differ among the States. Appendix A presents a list of all States used in the analyses.