National evaluation of graduated driver licensing programs.

Implementation of Graduated Driver Licensing (GDL) programs is associated with reductions in crash rates of young drivers, but the contribution of specific components of GDL programs is not known. Objective. To determine which types of GDL programs are associated with reductions in fatal crashes involving 16-year-old drivers. A retrospective study was performed of involvement of 16-year-old drivers in fatal crashes in the United States from 1994 through 2004 using data obtained from the Fatality Analysis Reporting System (FARS) and the US Census Bureau. The association of various GDL programs with fatal crashes involving 16-year-old drivers was examined and compared to results for 20-24 and 25-29-year-old drivers. Analysis was based on the total number of quarters of the year in all States (“State-quarters”) with or without specific GDL programs, excluding the four quarters before and the four quarters after a law was changed. Main outcome measure was Incidence Rate Ratio (IRR) for fatal crashes involving 16-year-old drivers in relation to GDL programs. Overall, State-quarters having GDL programs (combined results, including weaker programs) were associated with an 11% reduction [IRR 0.89, 95% confidence interval (CI) 0.80, 0.99)] in fatal motor vehicle crashes involving 16-year-old drivers, compared to State-quarters without GDL. When State-quarters without any of the 7 components are compared to State-quarters with GDL programs, only those programs having five or more components experienced a significant reduction (18%-21%). Reductions of 16% to 21% occurred with programs that included age requirements plus: 3 or more months of waiting before the intermediate stage, nighttime driving restriction, and either supervised driving of at least 30 hours or passenger restriction. The finding that GDL is associated with reductions in fatal crashes is strengthened by the observation that drivers aged 20-24 or 25-29 years did not experience similar reductions in fatal crash rates. The most comprehensive GDL programs are associated with reductions of about 20% in 16-year-old drivers’ fatal crash involvement rates. Based on existing programs that were sufficiently common for analysis, the greatest benefit appears to be in programs that include age requirements plus: 3 or more months of waiting before the intermediate stage, nighttime driving restriction, and either supervised driving of at least 30 hours or passenger restriction. (Author/publisher) See also C 36338 fo.