Child/Adolescent Health

Zero tolerance of alcohol for drivers under age 21 reduces drinking and driving among college students

Zero tolerance laws that exact strict penalties for any alcohol use for drivers under age 21, enforced since 1998, have reduced drinking and driving among college students, a new study shows. Lan Liang, Ph.D., of the Agency for Healthcare Research and Quality, and Jidong Huang, of NERA Economic Consulting, used data from the 1993, 1997, and 1999 waves of the College Alcohol Surveys (CAS) to examine the effects of zero tolerance laws on drinking patterns.

An alarming number of college students drove after drinking and binge drinking in the month prior to the surveys. For example, in 1999, more than two out of every five drinkers reported driving after drinking and one of every five reported driving after binge drinking (five or more drinks). Overall, zero tolerance laws reduced binge drinking, drinking away from home, and driving after drinking, especially among those who drank away from home. Specifically, zero tolerance laws reduced binge drinking by 1.6 to 1.9 percentage points, a 3 to 4 percent reduction from pre-zero tolerance laws, and reduced drinking and driving among drinkers by 4 to 5 percent, a 14 to 17 percent reduction from the prelaw mean.

Zero tolerance laws reduced drinking away from home by about 7 percent, but were not associated with any increase in home drinking among on-campus students. Zero tolerance laws were also associated with a 26 to 27 percent reduction in the probability of drinking and driving among those who reported drinking away from home.

See "Go out or stay in? The effects of zero tolerance laws on alcohol use and drinking and driving patterns among college students," by Drs. Liang and Huang, in Health Economics, 2008, which is available online at www.interscience.wiley.com.

Reprints (AHRQ Publication No. 08-R053) are available from the AHRQ Publications Clearinghouse.

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