by Patrick Appel
What caused it?:
If walking is a casualty of modern life the world over—the historian Joe Moran estimates, for instance, that in the last quarter century in the U.K., the amount of walking has declined by 25 percent—why then do Americans walk even less than people in other countries? Here we need to look not at pedometers, but at the odometer: We drive more than anyone else in the world.