Having grown up in Europe until I was ten, I was very familiar with the traffic roundabout and always wondered why we did not have them here in the U.S. Then, a few years ago they started popping up in neighborhoods and now we even have one in front of Lenox Mall in Atlanta. Almost 145 roundabouts have been constructed in Georgia in the last 10 years with over 100 more on the drawing board. By comparison, in the ’90s, there were less than 100 roundabouts in the U.S and that number has skyrocketed to over 2,300 today. See http://roundabout.kittelson.com/.
As a lawyer who deals with traffic accidents, I have studied roadway design and when you look at the massive benefits of roundabouts over traditional intersections, it’s not even close.
Roundabouts have two huge advantages over traditional intersections in that drivers rarely come to a complete stop, which reduces traffic backups and yet they are forced to slow down so that there are much fewer opportunities for cross-traffic turns that lead to hard head-on or T-Bone collisions. By comparison, traffic studies have shown that there are 32 places in a traditional intersection where cars can cross each other’s path versus only 8 in a roundabout.
In a 2007 report from the Transportation Research Board (an arm of the National Academies of Science, Engineering, and Medicine) that studied 55 intersections before and after the installation of roundabouts.
Roundabouts vs. Traditional four-way intersections:
reduction in accidents by 35%
reduction in injuries from those accidents by 76%
reduction in fatal or serious injury accidents in urban roundabouts 81%
reduction in fatal or serious injury accidents in rural roundabouts 71%