WASHINGTON — The upper Midwest has the worst drunken driving rates in the country, according to a government report that says 15 percent of adult drivers nationally report driving under the influence of alcohol in the previous year.

Wisconsin leads the way. The federal government estimates more than a quarter of the state's adult drivers had driven under the influence. Rounding out the worst five are North Dakota, Minnesota, Nebraska and South Dakota.

Utah had the lowest incidence of drunken driving. It was the only state where fewer than 10 percent of adult motorists reported driving under the influence. Following closely behind were a slew of Southern states that often fare poorly when it comes to government health statistics. This time, however, they're serving as models. West Virginia, Arkansas, Kentucky and North Carolina all had drunken driving rates for the prior year of less than 11 percent.

The report on drunken driving relies on data obtained from the National Survey on Drug Use and Health. The survey, based on a scientific random sample of households, asked 127,283 adults in 2004, 2005 and 2006 whether they had driven under the influence in the past year. Health experts say the state-by-state breakdowns support other surveys showing that residents in northern states are more likely to engage in heavy alcohol consumption.

"It's not surprising, but it means that these jurisdictions should take this data and think about how they approach public education campaigns and enforcement campaigns," said Dr. H. Westley Clark of the Substance Abuse and Mental Health Services Administration, which released the report. The agency is a part of the Department of Health and Human Services.

Eric Goplerud, research professor at George Washington University Medical Center, said cultural and demographic issues probably have a role in the higher rates of driving under the influence in certain states. He said that religious affiliations in the Southeast often strongly discourage drinking, but that doesn't occur so much in the upper Midwest.

"A good part of the social life is around drinking," said Goplerud, who is also director of Ensuring Solutions to Alcohol Problems, which call for increased access to treatment programs.

Also, blacks drink at substantially lower rates and at less hazardous rates than whites, he said. The populations in those states are heavily white.

Jeffrey Ratliff-Crain, associate professor of psychology at the University of Minnesota-Morris, noted that the Minnesota Legislature is considering a bill that would let bars stay open until 4 a.m. during the Republican National Convention, pouring more money into the economy.

"We're making it easier to drink to all hours of the night, but (drinking and driving) didn't come into the discussion," Ratliff-Crain said. "There is a seeming acceptance that this is the way it is. Of course people are going to be drinking and driving, and well, that's it."