Here's the theory: Old people are bad drivers. And we're living longer, so there are more old people on the road, so they're causing more accidents. And they're already fragile, so they're killing more people, including themselves. Right?
Wrong. According to the latest data from the Insurance Institute for Highway Safety (flagged by Tara Parker-Pope of the New York Times ), it's true that "older people now hang onto their licenses longer, drive more miles, and make up a bigger proportion of the population than in past years as baby boomers age." It's also true that "per mile traveled, crash rates and fatal crash rates increase starting at age 70 and rise markedly after 80," possibly because "physical, cognitive, and visual declines associated with aging may lead to increased crash risk."
That's what makes the bottom-line findings so surprising:
Despite growing numbers on the road, fewer older drivers died in crashes and fewer were involved in fatal collisions during 1997-2006 than in years past. ... Crash deaths among drivers 70 and older fell 21 percent during the period, reversing an upward trend, even as the population of people 70 and older rose 10 percent. Compared with drivers ages 35-54, older drivers experienced much bigger declines in fatal crash involvements.
The institute's chief of research adds: "No matter how we looked at the fatal crash data for this age group—whether by miles driven, licensed drivers, or population—the fatal crash involvement rates for drivers 70 and older declined, and did so at a faster pace than the rates for drivers 35-54 years old."
So what gives? "Reasons for the fatality declines aren't clear, but another new Institute study indicates that older adults increasingly self-limit driving as they age and develop physical and cognitive impairments," says the IIHS. In that study,
The oldest drivers were more likely to say they restricted their own driving. Drivers 80 and older were more than twice as likely as 65-69 year-olds to self-limit driving by doing such things as avoiding night driving, making fewer trips, traveling shorter distances, and avoiding interstates and driving in ice or snow. The percentage of drivers who said they limit their driving increased with each added degree of impairment. Drivers cited memory and medical impairments more often than vision or mobility ones.
In other words, as we age, self-knowledge and self-regulation compensate for our loss of abilities. As Farhad Manjoo reported four months ago in Slate ,
Statistics on current road deaths show that people over the age of 65 are only 16 percent more likely to cause accidents than are people aged 25 to 64. Drivers under 25 , meanwhile, are the most dangerous people on the road—they're 188 percent more likely to cause crashes than middle-aged adults .
Aging is a tragic but beautiful process: As we decay in some ways, we grow in others. We become less able to control the world but more able to control ourselves. As IIHS points out, our decline isn't just physical; it's mental, too. Yet we understand ourselves better than ever. Even as our vision deteriorates, we become more clear-eyed about our own limits. And even as our memory degrades, we develop a more important kind of knowledge: We know what we don't know.
Not everyone grows this way. To the extent that self-regulation has reduced fatal crash rates among aging drivers, the implication is that old people can be made more aware of their limits and can adjust accordingly. If you're aging, the lesson is to monitor and govern your driving. And if you're young, the lesson is to cultivate what old people have—self-knowledge and self-control—while your mind and body are still at full strength.