Jackson Circle at Horseferry Road (Carmel, Indiana) was voted "Roundabout of the Year" in 2016 by the U.K. Roundabout Appreciation Society.
In the United States, the earliest roundabouts often were constructed in bigger cities. In general, our analysis shows, they’re most likely to be built in well-educated, high-income towns. These days, the fastest growth is in suburbs and rural areas...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.
More information at The Washington Post.