Michigan's graduated driver licensing program: evaluation of the first four years.
BACKGROUND
To evaluate the four-year outcome of Michigan's graduated driver licensing (GDL) program, motor-vehicle crash data for 16-year-old drivers in 1996 (pre-GDL), and 1998-2001 (post-GDL) were analyzed.


METHODS
Relative risks and 95% confidence intervals for several crash types were computed, and pre-post-GDL population-based crash rates were compared. Reductions in crash risks among 16-year-olds previously found in 1998 and 1999 were generally maintained in 2000 and 2001.


RESULTS
Reductions in crash risk among 16-year-olds from 1996 to 2001 were 29% for all, 44% for fatal, 38% each for nonfatal-injury and fatal-plus-nonfatal-injury, 32% for day, 31% for evening, 59% for night, 32% for single-vehicle, and 28% for multi-vehicle crashes. Even after adjusting for more general population-wide changes among drivers 25 years and older that might have contributed to changes in 16-year-old crash risk, reductions remained impressive (19% for all crashes in 2001).


CONCLUSIONS
As one approach to reducing teenage motor-vehicle morbidity and mortality, GDL remains promising.
Shope
Jean T
JT
University of Michigan Transportation Research Institute, 2901 Baxter Road, Ann Arbor, MI 48109-2150, USA. jshope@umich.edu
Molnar
Lisa J
LJ
D000063:Accidents, Traffic / Q000517:prevention & control / Q000639:trends; D000293:Adolescent; D001334:Automobile Driving; D005260:Female; D006801:Humans; D008004:Licensure / Q000331:legislation & jurisprudence*; D008297:Male; D008824:Michigan; D014947:Wounds and Injuries / Q000453:epidemiology / Q000517:prevention & control