According to a study based on data from New Zealand, lowering the drinking age increases car crashes among youth. The drinking age was lowered from 20 to 18 in 1999. The study found that the rate of traffic crashes and injuries increased 12% for 18-19 year old males and 14% among 15-17 year old males comparing the four years before and after the New Zealand legislature lowered the drinking age to 18. For females, rates rose 51% for 18-19 year olds and 24% for 15-17 year olds. The study estimated that 400 serious injuries and 12 deaths each year among 15-19 year olds could be prevented if New Zealand raised their minimum legal drinking age.

There is no traffic safety policy with more evidence for its effectiveness than minimum legal drinking age laws, according to Robert B. Voas, one of the study's authors. Traffic crashes by young drivers were declining in New Zealand when that country decided to lower its drinking age. Thereafter, the overall road toll for those drivers rose dramatically. Most remarkable was the trickle-down effect that was seen in the 15- to 17-year-olds, Voas said. Clearly, they're getting alcohol from older friends.

People in the United States who argue for lowering the drinking age should pay attention. Currently, there are five U.S. States that have legislation pending to lower their minimum legal drinking age. The outcomes found in the New Zealand study are similar to those from the United States after drinking ages were lowered in many states the early 1970s. A number of studies on the effects of those drinking age changes showed a substantial increase in traffic crashes involving young people. Today, all 50 states have a minimum 21 drinking age.

This study was published in the January 2006 edition of the Journal of American Public Health. The study was authored by Kypros Kypri, Robert B. Voas, John D. Langley, Shaun C.R. Stephenson, Dorothy J. Begg, A. Scott Tippetts, and Gabrielle S. Davie.

Reprinted from the Winter 2006 issue of the Reporter, the newsletter of the International Council on Alcohol, Drugs and Traffic Safety.

Kypri, K., Voas, R.B., Langley, J.D., Stephenson, S.C.R., Begg, D.J., Tippets, A.S., & Davie, G.S. (2006). Minimum Purchasing Age for Alcohol and Traffic Crash Injuries Among 15- to 19-Year-Olds in New Zealand. American Journal of Public Health, 96(1), 126-131.