Legal and social reform did not solve the problem of drunk driving, and solving the problem presents an unrealistically high bar. We still have drunk driving, we still have too much of it, and people still die from it. But the National Institutes for Health calculates that policy changes prevented something on the order of 150,000 deaths from 1982 to 2001 and continue to prevent about 1,000 traffic deaths a year. That’s something.

How did we manage that?

Libertarians may wish to avert their gaze, but prohibition played a big role in that. As NIH runs the numbers, the single policy change that had the most significant effect was raising the legal drinking age from 18 to 21. Some of you will remember that the states did this under duress, with Washington threatening to withhold highway funds from non-compliers under the National Minimum Drinking Age Act of 1984. The federal law did not call for a ban on alcohol consumption by those under 21, but only on sales. This had the effect of moving teenage drinking from bars and restaurants to house parties and other settings where young drinkers might be less likely to drive — and where arranging for alcohol to be served required some organization and forethought, qualities not generally associated with the general run of 19-year-olds.

There were other legal changes as jurisdictions around the country adopted stricter laws on drinking while driving (before “open container” laws, one could drink a beer or two while behind the wheel) and on drunk driving per se, including “zero tolerance” laws that mandated the loss of driving privileges or other, more severe penalties for underage drunk drivers. This probably has gone too far, with the current prevalent blood-alcohol content threshold (0.08 percent) rendering some smaller men and women legally drunk after consuming a glass of Bordeaux with dinner.