Graduated driver's licenses reduce motor vehicle crashes. (Drinking & Driving).

A program of graduated driver licensing instituted in the state of Michigan has significantly reduced motor vehicle accidents among teenagers, according to an article published in the Journal of the American Medical Association.

The licensing changes delay the age at which young drivers can obtain full licensure, increase their driver training, and limit their ability to drive in high-risk situations and at high-risk times, say authors from the University of Michigan's Transportation Research Institute.

Jean T. Shope, Ph.D., M.S.P.H., and colleagues examined changes in the rate of fatal and nonfatal automobile accidents among 16-year-old drivers in 1996, and then again in 1998 and 1999. Michigan's Graduated Driver Licensing (GDL) program, which was instituted in 1997, requires teens to complete three levels of licensure. Level 1 is the learner's stage, during which teens may drive only in the company of a licensed adult after completing 24 hours of classroom instruction and six "road hours"; Level 2 is the intermediate stage, during which teens may drive between the hours of midnight and 5 a.m. only with an adult and only after …