The ‘Quiet Roundabout Revolution’ Sweeping U.S. Cities

Although a lack of federal data makes it difficult to evaluate the scale of their growth, roundabouts and traffic circles are slowly but surely making their way into American cities, writes Andrew Van Dam in the Washington Post.

According to Lee Rodegerdts, who literally wrote the book on roundabouts—Roundabouts: An Informational Guide—there are now roughly 9,000 roundabouts around the country, plus over 160 rotaries and more than 700 traffic-calming circles.

Florida boasts the most roundabouts, but it also has the third-largest population in the nation. Nebraska has the most roundabouts per person, but they’re spread across one of the sparsest (and often most scenic) road networks in the country. Per mile of road, Maryland actually emerges as the roundabout champion.

As far as cities go, the wealthy enclave of Carmel, just outside Indianapolis, has more roundabouts than any other U.S. locality thanks to its long-term mayor, who has championed roundabouts for decades. Carmel has built more than 140 roundabouts under his tenure.

“Why add a roundabout, you might ask. Because roundabouts offer impressive safety gains. In general, a roundabout will drive down fatal crashes by 90 percent and cut all car-crash injuries by at least 75 percent, even while accommodating a higher volume of cars.” The benefit is even greater at rural two-way stops, cutting traffic injuries by as much as 90 percent.