Look around while driving Utah's roads and highways, Gretchen Clark says.

Count the cars around you in the logjam at 10600 South and I-15.

If you travel a lot like she does between Salt Lake City and St. George, see how many pass by 18 inches away in the lanes to the right and left.

Look at all the cars around you. Look at their drivers and see if it makes new statistics about drunken driving in Utah hit any closer to home.

A study of DUI offenses over 10 years shows about 5 percent of Utahns have been arrested for drunken driving. And of that pool of drunken drivers, one-quarter are repeat offenders, according to the data, compiled from driver license records by Jennifer Hemenway of the state's Commission on Criminal and Juvenile Justice.

Those are only the people arrested or convicted, said Clark, whose son was killed by a drunken driver several years ago.

"Statistics about the those potential drunk drivers — those I see when I drive back and forth to St. George — the risk we all face is probably untrackable," said Clark, who was involved with Parents Against Drunk Driving, a grass-roots advocacy group that existed before a Mothers Against Drunk Driving chapter came to Utah.

The new report is significant in Utah's ongoing battle against the problem of drinking and driving because demographic information here is so disorganized that there has been virtually no way to draw a clear profile of a drunken driver.

And advocates who fight for tougher sentences and drunken-driving laws say they desperately need this data to build public-awareness campaigns, so they can draw some conclusions from the report's details: such as the fact that Utah repeat offenders don't mess around when it comes to being re-arrested for driving drunk. According to the report, nearly 25 percent of those who are caught drinking and driving again did so within six months.

"What this shows us is that it's probably very much with them an addiction," said Art Brown, an advocate for victims of drunken driving on the statewide council now tackling these issues. "It tells us they have to have the treatment component and they have to be separated from their cars by an (ignition) interlock or some other means."

Advocates of tougher drunken driving laws have testified for years that about 20 percent of drunken drivers are repeat offenders. The new data shows that number is actually 25 percent.

That's an indication that more people are repeating these offenses or police and prosecutors are doing a better job of identifying who's been caught drinking before and who's committing the offense for the first time.