Superfreakonomics_ global cooling, patri - Steven D. Levitt [67]
That’s a big reason the per-mile auto fatality rate has fallen so much in the United States. Seat belts reduce the risk of death by as much as 70 percent; since 1975 they have saved roughly 250,000 lives. Traffic fatalities still claim more than 40,000 lives a year, but relatively speaking, driving isn’t all that dangerous anymore. What makes the death toll so high is that so many Americans spend an enormous amount of time in their cars, racking up some 3 trillion miles per year. That translates into one death for every 75 million miles driven—or, put another way, if you drove 24 hours a day at 30 miles per hour, you could expect to die in a car accident only after driving for 285 straight years. Compared with the death rates in many countries in Africa, Asia, and the Middle East, where seat-belt use is far less prevalent, driving in the United States isn’t much more dangerous than sitting on your couch.
And seat belts, at about $25 a pop, are one of the most cost-effective lifesaving devices ever invented. In a given year, it costs roughly $500 million to put them in every U.S. vehicle, which yields a rough estimate of $30,000 for every life saved. How does this compare with a far more complex safety feature like air bags? At an annual U.S. price of more than $4 billion, air bags cost about $1.8 million per life saved.
Robert McNamara, who recently passed away at the age of ninety-three, told us shortly before his death that he still wanted to get to 100 percent compliance on seat belts. “A lot of women often don’t use the shoulder belt because they’re uncomfortable, they’re not designed to take account of the breasts,” he said. “I think with very little thought, belts could be designed that are more comfortable and therefore increase the percentage of use.”
He may or may not be right about women and seat belts. But without doubt there is one group of people for whom seat belts are poorly designed: children.
Sometimes it pays to be low status. When a family of four goes for a drive, the kids usually get shunted to the backseat while the mom or dad rides shotgun. The kids are luckier than they know: in the event of a crash, the backseat is far safer than the front. This is even truer for adults, who are larger and therefore more likely to smack into something hard when they sit up front. Unfortunately, while it’s okay to consign the low-status kids to the rear seat, if the parents go out for a drive alone, it’s a bit awkward for one of them to ride in the back while leaving the other up front in the martyr’s seat.
Seat belts are now standard issue in the rear seat of all cars. But they were designed to fit grown-ups, not kids. If you try to strap in your three-year-old darling, the lap belt will be too loose and the shoulder belt will come across his neck or nose or eyebrows instead of his shoulder.
Fortunately, we live in a world that cherishes and protects children, and a solution was found: the child safety seat, commonly known as a car seat. Introduced in the 1960s, it was first embraced by only the most vigilant parents. Thanks to the advocacy of doctors, traffic-safety experts, and—surprise!—car-seat manufacturers, it came into wider use, and the government eventually joined the party. Between 1978 and 1985, every state in the United States made it illegal for children to ride in a car unless they were buckled into a safety seat that met federal crash-test standards.
Motor-vehicle accidents were the leading cause of death for U.S. children back then, and they still are today, but the rate of death has been falling dramatically. Most of the credit has gone to the car seat.
Safety isn’t free, of course. Americans spend more than $300 million a year buying 4 million car seats. A single kid will typically inhabit three different seats over time: a rear-facing seat for infants; a larger, front-facing