According to this article in the Minneapolis StarTribune, 1 in 8 Minnesota drivers has been arrested for DUI. The state patrol estimates that there are more than 500,000 drivers licensed by the state who have been arrested. This is an incredible figure. I can't think of any other law that is broken so frequently in light of the amount of information and enforcement efforts. This is particularly striking because the consequences of a DUI are quite severe, and for many people the costs of driving after a DUI conviction are prohibitive. And I can't imagine that drivers don't know this before they drink and drive.
The article also states that the average blood-alcohol concentration was .17, or more than twice the legal limit. These arrests are clearly not the case of overzealous enforcement against moderate social drinkers. These people shouldn't be on the road.
However, I'm skeptical of the claim of 500,000 offenders. During the month of December, which was a coordinated month of extra heavy enforcement, there were 3,350 arrests. If there were that many arrests each month-which isn't the case, obviously-that would take almost 13 years to reach 500,000. I also wonder how many of the 500,000 are repeat offenders. I suspect that quite a few are. As most of the booze is bought by a relatively small group of drinkers, I suspect that most alcohol related crimes (including DUI) are committed by a small group of offenders.
Alternately, if it is true that 1 in 8 Minnesota drivers have been arrested for DUI (though there is no claim for how many have been convicted, though I am sure it is a smaller number), what does this say about the policy? It seems that driving drunk is popular (though not advised). A more acceptable policy critique is that the education against drunk driving only works so well. We may have hit the end of the road for getting the social drinkers off the road as they are likely to have responded to the threat of arrest and punishment. The remaining drunk drivers have decided to continue their bad habit. Perhaps increased enforcement is the most cost effective way to achieve results.
One last point is that since most of these arrests were of people who were way above the limit, I think there is little to be gained and a fair amount to be lost by continuing to lower the legal limit of BAC. Further reductions would negatively impact restaurants and other desirable activities but will likely have little impact on worst drunk driving offenders. A lower BAC will greatly increase the potential number of offenders, however. But the policy is probably not improved by going after those who test between .04 and .08. The people who blow .17 are a much greater danger.