November 18, 2011

SCIENTIST PROVES THAT DRUNKS ARE SURPRISINGLY GOOD DRIVERS. Okay, that’s not the tenor of the piece. But what else to make of this bit?

Now, alcohol-related deaths from crashes are down to about 10,000 or 11,000 a year.

“There’s been a lot of progress, and I wouldn’t want to minimize that. But I saw a recent statistic put out by the CDC that suggested that there are least 110 million instances of drunk driving in this country still a year,” Lerner says.

Do the math: 11,000 deaths from 110 million instances is a 1-in-10,000 risk of death from an instance of drunk driving. That doesn’t sound so bad. But of course, an “alcohol-related crash” is just one in which someone has been drinking, not necessarily a crash in which drunk driving was the cause, so the risk is probably even lower. Hey, you can’t argue with science!

Maybe we should just abolish drunk driving laws. “Several studies, such as a 2005 paper in the British Medical Journal, have found that talking on a cell phone, even with a hands-free device, causes more driver impairment than a 0.08 BAC. A 2001 American Automobile Association study found several other in-car distractions that also caused more impairment, including eating, adjusting a radio or CD player, and having kids in the backseat. . . . Doing away with the specific charge of drunk driving sounds radical at first blush, but it would put the focus back on behavior, where it belongs. The punishable act should be violating road rules or causing an accident, not the factors that led to those offenses. Singling out alcohol impairment for extra punishment isn’t about making the roads safer. It’s about a lingering hostility toward demon rum.”

UPDATE: Reader Donald Stephens writes:

I’m a traffic engineer, so I ran the basic statistics for all fatalities and all vehicle trips to get a basis for comparison.

I used the 2009 fatality data (the most recent readily available) and historical trip data. There are about 813 million, more or less, trips in a typical year – 2009 may have been less because of the recession but I’ll ignore that for now. 2009 had about 33,800 total fatalities (rounded to three figures) and 10,900 alcohol involved crashes (BAC > .08).

Using the 110 million drunk-driving trip estimate the fatality rates are one in 10,200 for drunk-driving trips and one in 30,700 for non-drunk trips. The ratio is about three to one so it’s still an important concern. The economist’s question still comes into play: compared to what?

The really useful breakdown would be to cross-tab the fatalities, by BAC level, by total trips, by person. With that we could ask if habitual offenders and/or alcoholics more dangerous than occasional drunks. That would allow more effective enforcement and intervention than the current press-release-checkpoint system. (Bar stakeouts appear to be more efficient in producing arrests.) Unfortunately that data isn’t available.

Yes, the “compared to what?” question seldom gets asked. In addition, a rate of less than one fatality per 10,000 is comparatively low — at least, if they ran drunk-driving ads stressing a 1-in-10,000 risk of death, I don’t think it would make much of an impression.