SACRAMENTO, Sept. 14 (UPI) — U.S. graduated driver licensing programs reduce fatal crashes by 16-year-old drivers but are linked to more fatal crashes in 18-year-olds, researchers say.
Scott V. Masten of the California Department of Motor Vehicles in Sacramento and colleagues analyzed quarterly data from 1986 to 2007 of the incidence of fatal crashes involving drivers ages 16-19 in all 50 states and the District of Columbia.
Masten, Robert D. Foss of the Highway Safety Research Center and Stephen W. Marshall of the University of North Carolina at Chapel Hill say each state has different requirements as part of their programs — those that restrict driving after dark and passengers in the vehicle are considered strong programs — and the researchers combined the data of strong programs and weak programs.
The study, published in the Journal of the American Medical Association, found since 1996 graduated driver licensing was associated with 1,348 fewer fatal crashes involving 16-year-old drivers but 1,086 more fatal crashes involving 18-year-old drivers.
Stronger programs were linked with lower incidence of fatal crashes for 16-year-old drivers compared with weaker programs, the study says.
However, the researchers say they can only speculate on why the fatal crash rate was higher for those ages 18 and older. They say while the mandatory periods of supervised driving clearly reduce risk in the youngest drivers, supervised driving is co-driving and some important lessons of experience — such as self-regulation and being fully responsible for a vehicle — may not be learned until teens drive alone.