Young drivers are less likely than adults to drive after drinking, but their crash risk is substantially higher when they do. Many states raised minimum alcohol purchasing ages from 18 or 19 years old to 21 during the 1980s. However, enforcement is needed to make these laws even more effective. Early research from states where this policy has been implemented, including states where zero is the legal alcohol limit for teenagers, indicates it might reduce teenagers' nighttime fatal crashes. This kind of system means drivers are older and more experienced behind the wheel when they get their unrestricted licenses.
Evaluations indicate New Zealand's system successfully reduces teenagers' crashes.
The success of graduated licensing systems abroad has led to the introduction of similar programs in Florida, Georgia, Illinois, Louisiana, Michigan, New Hampshire, and North Carolina. Formal evaluations of U.S. high school driver education programs indicate little or no effect in reducing crashes per licensed driver. The net result is more crashes per capita among teenagers. Connecticut eliminated high school driver education and lowered teenage crash rates by reducing licensure. High school driver education programs can successfully teach driving skills, and programs warning against alcohol-impaired driving can impart knowledge about this behavior.