Does Speed Kill?

I was around for the debates in the mid-80’s and late 90’s about raising the speed limit, from 55 to 65, and from 65 to 70 and up, respectively. The tradeoff seemed fairly simple to me: you get to drive faster, at greater risk, to yourself and the rest of the drivers out there. Which did we as a community prefer?

Of course, the debate didn’t turn out quite that way. There are a lot of people who argue that speed and safety are not correlated; occasionally citing statistics that as average speeds have increased, fatalities have dropped. Well, I haven’t really dug into the studies, and seen whether they correct for things like safer cars, safer highways, and a faster-moving-thinking population, but call me skeptical. My uninformed opinion is these people are playing psychological tricks on themselves. They want to drive fast, so they talk themselves into believing that they are being safer. It seems pretty clear to me that the faster you go, the less reaction time you have, and the greater the force of impact when you smash into something. Call me crazy, but that can’t be good for either the accident or the fatality rate.

I have, however, heard one argument for higher speed limits that was at least half-respectable. On long stretches of rural highways, faster speeds mean you can save hours on long trips, and that reduces the likelihood of fatigue, which significantly contributes to accidents. I’m not totally sure what to make of this argument – certainly fatigue is bad; it’s just not clear exactly what the right tradeoff is. But it’s certainly a reasonable thing to say.

Which led me to perform a thought experiment. Suppose the speed limit was set to be something ultra-conservative; say 30 mph. And for the sake of argument, suppose that compliance was pretty good, so people really did drive that speed. What would happen? My guess is that people would get so bored that they would start multi-tasking like crazy to the point where they barely kept any focus on the road. I mean, it’s already no big deal to see people hauling down the road at 70 mph while yakking on the cell phone, shaving, putting on makeup, eating, listening to music, talking to passengers or kids in the back seat, or some combination of the above. All that when a five second lapse in concentration can kill you (and does kill plenty of people each year). Heck, I’ve even seen people driving on Wadsworth while reading a newspaper. God only knows what people would be doing if you slowed them down to only doing 30? Watching movies? Playing World of Warcraft?

So what I’m saying is that I do actually see the point of Peltzman-like theories (see the previous post) that people can have a sort of internal “risk thermostat”, whereby they have some level of risk that they are comfortable with, and if you constrain them to be safe in one dimension then they will compensate in some way by taking risks in other areas.

All that being said, I still find it hard to believe that drivers have become less safe as seatbelt adoption has gone up. Most people I know don’t want to be in a major crash, period, whether they think they’ll live through it or not. I don’t see the fact that their chances of surviving a major crash have gone up means that they are all of a sudden more tolerant of smashing into things.

Interesting topic though. I should check into the insurance angle. After all, the same theory would predict that people who are insured should be riskier drivers, and that uninsured drivers are safer. Although that’s counterbalanced by the fact that many uninsured drivers are that way because they suck and can’t get insurance.