The New York Times reports that prosecutors looking for ways to bring charges against people who drive while sleep-deprived.*
They're having problems doing so because some people need more sleep than others, and some people function better than others when deprived of sleep. But of course, you can say the same thing about alcohol.
The difference is that we have a way to measure how much alcohol is in a driver's bloodstream. It has its limitations. Blood-alcohol concentration can vary by height, weight, and genetics. And within all of that variation, some people function better than others at different BAC levels. It's just a poor way of measuring impairment. But it is a way to come up with a number. And we seem to be comfortable convicting people based on numbers, even if they're fairly arbitrary.
One reason we don't have similar strict laws against driving while sleep deprived is that we don't have a test to measure sleep deprivation. (Latent Puritan attitudes toward alcohol are probably a factor too.) If there were some crude test to measure it, we'd probably be convicting people by now, regardless of whether the method of measurement actually did much to make the roads safer.
There are similar problems with attempts to ban the use of cell phones while driving. Yes, it's dumb and unsafe to use your cell phone in the car. Most of the time. But laws prohibiting it don't necessarily make the roads safer. In fact, they might make things worse.
The answer, as I've argued before, is to scrap the under-the-influence model altogether. Stop focusing on why people drive poorly and start punishing them for driving poorly. A family of four killed when an oncoming car hops the median is no less dead if the driver was a mom distracted by her kids in the back seat, a drunk driver, or a teenager who lost control while sending a text message.
If you want to crack down on highway deaths, pass more severe penalties for reckless driving, regardless of the cause. You could gradually at more punishment for someone who causes an accident, causes injury, or causes a fatality. But the actual breaking of traffic laws should be the crime. When you focus on the cause of impairment, you get problems like Fourth Amendment-stretching sobriety checkpoints, or cops authorized to draw blood along the side of the road. Cell phone and texting bans become another excuse for cops to make pretext stops while drug profiling.
Finally, when we discuss what new laws we need to make the roads safer, it's good to remember that highway fatalities have been in decline for decades. And that's happened over period in which distracted driving has increased exponentially.
(*Did you notice I linked to the mobile version of the NYT story? I wrote this entire post on my cell phone while stopped at a red light.**)
(**Kidding! Although given the length of the typical red light in Nashville, it's probably doable.)