Alcohol-related crashes are reduced when police immediately suspend the driving privileges of drivers charged with drunk driving, according to a new study.

Scientific American reported July 24 that researcher Alexander Wagenaar and colleagues at the University of Florida College of Medicine found that "preconviction license suspension laws are clearly successful in reducing the rates of alcohol-related crashes," whereas "postconviction laws have virtually no effect."

The researchers estimated that taking away the licenses of anyone who fails a field sobriety test cut drunk-driving fatalities by 5 percent and saves about 800 lives annually. The study was based on an analysis of 26 years of federal crash data from 46 states with driver's license suspension laws on the books.

Experts say that swift punishment has been shown to be more effective than delayed sanctions. Only nine states allow drivers to keep their licenses if they fail a field sobriety test: Kentucky, Michigan, Montana, New Jersey, New York, Pennsylvania, Rhode Island, South Dakota and Tennessee.

The study was published in the August 2007 issue of the journal Alcoholism: Clinical and Experimental Research.