By Tom Vanderbilt
October 18, 2010

American roads are safer than ever, according to the Department of Transportation. But that positive development masks a more regrettable trend: once the world's least dangerous place to drive, the U.S. is now 12th in its rate of road deaths per miles driven, a new International Transport Forum report shows. On a per capita basis, the U.S. falls to 28th, pinched between Cambodia and South Korea.

While there are myriad factors in this slide, one in particular deserves a look. Roundabouts, the circular alternatives to stoplights, are common abroad, where they eliminate one of driving's most dangerous moves—the left turn against oncoming traffic—and can reduce fatal accidents by as much as 90 percent.

Fortunately, the U.S. is also starting to think inside the circle. Maryland, Missouri, and Georgia have built dozens of roundabouts in recent years, and hundreds more are in the works nationwide. But Carmel, Ind., is leading the nation, having built about 60 since 2001. For a city that claims “one of the country's first automatic stop-and-go traffic signals,” it's saying something that the lights are now being torn down. The benefits, however, may say something more: in the revamped intersections, there has been an 80 percent drop in crashes involving injuries.