Graduated driver licensing reduces fatal crashes

Graduated driver licensing programs reduce, by an average of 11 percent, the incidence of fatal crashes of 16-year-old drivers, according to a study by researchers from the Johns Hopkins Bloomberg School of Public Health's Center for Injury Research and Policy and the Johns Hopkins School of Medicine.

When examining the most comprehensive programs (19 states), which include at least five of seven components, the researchers found about a 20 percent reduction in fatal crashes involving 16-year-old drivers. The report was supported primarily by the National Highway Traffic Safety Administration (NHTSA) and in part by the Centers for Disease Control and Prevention.

"Graduated driver licensing programs are a popular way to reduce the risk of vehicle crashes for novice drivers. We already knew that the programs reduced crash rates of young drivers, but we didn't know which programs were most effective in reducing risk," said Susan P. Baker, MPH, lead author of the study and a professor in the Bloomberg School of Public Health's Department of Health Policy and Management and Center for Injury Research and Policy. "After completing our study, it is clear that more comprehensive programs have the greatest effect."

"This study strongly underscores the effectiveness of graduated licensing laws. To states searching for solutions to the tragic problem of fatal crashes involving teenagers, it provides extremely valuable new information," said Nicole Nason, NHTSA Administrator.

Graduated driver licensing programs differ in each state. The Hopkins researchers based their analyses on the presence of the following components, chosen for analysis because they are commonly found in existing programs:

• A minimum age of 15 1/2 for obtaining a learner permit
• A waiting period after obtaining a learner permit of at least 3 months before applying for an intermediate license
• A minimum of 30 hours of supervised driving
• Minimum age of at least 16 years for obtaining an intermediate state license
• Minimum age of at least 17 years for full licensing
• A nighttime driving restriction
• A restriction on carrying passengers

The researchers used data from 1994-2004 collected by NHTSA's Fatality Analysis Reporting System and the U.S. Census Bureau to examine various graduated driver licensing programs and fatal crash statistics in 36 U.S. states with graduated driver licensing programs and 7 without.

Comparing states with five program components to states without graduated driver licensing programs, the researchers reported an 18 percent reduction in fatal crashes involving 16-year-old drivers. Programs with six or seven components were associated with a 21 percent reduction. The researchers also found a 16-21 percent reduction in fatal crashes when programs included an age requirement in addition to a wait of at least three months before allowing teens to apply for their intermediate-stage license, plus nighttime driving restrictions and either 30 hours of supervised driving or passenger restrictions. The authors concluded that the most comprehensive graduated driver licensing programs result in the best reduction of fatal crashes of 16-year-old drivers.

In addition, the authors' findings were strengthened by examining fatal crashes involving drivers aged 20-24 and 25-29. The researchers did not find a reduction in fatal crashes in these age groups. Graduated driver licensing restrictions primarily affect 16-year-olds, indicating that the changes were not associated with the overall driving environment that would also have influenced older drivers, explained co-author Li-Hui Chen, PhD.

"Annually, about 1,000 16-year-old drivers are involved in fatal crashes in the United States and traffic injury is the leading cause of death among adolescents. The effectiveness of graduated driver licensing programs in reducing fatal crashes of novice drivers is very robust across genders and geographic regions. Enhancing the enforcement of graduated driver licensing regulations could prevent more premature deaths," said co-author Guohua Li, MD, DrPH.