Graduated driver licensing laws and insurance collision claim frequencies of teenage drivers

November 2009

Objectives: This study examined the effect of different graduated driver licensing (GDL) laws on collision claim frequencies of licensed and insured teenage drivers. Method: Automobile insurance collision claim frequencies were computed by year (1996-2008) and state for drivers ages 16-19. Poisson regression models were used to estimate the effect of GDL laws on claim frequencies. The claim frequency for drivers ages 35-55 was used as a covariate to control for non-GDL state and year variation in motor vehicle crashes. Results: Compared with GDL laws rated poor, laws rated good reduced collision claim frequencies of 16 year-olds by an estimated 20 percent. Laws rated fair and marginal reduced claim frequencies by 15 and 10 percent, respectively. Claim frequencies also were reduced for older teenage drivers, although to a smaller extent. Analyses of GDL components showed increasing license age, requiring practice driving, restricting passengers to one or fewer, and a strong nighttime driving restriction significantly reduced claim frequencies of 16-year-old drivers. Conclusions: GDL laws are reducing collision claim frequencies of young drivers, and stronger laws are having larger effects.