The roughly 3,700 circular traffic intersections in the U.S. are feared, avoided, and even loathed, often without good reason. This fear is rooted in the invention’s history. Early traffic circles (Columbus Circle in NYC is largely acknowledged as the first roundabout, built in 1905) were incredibly dangerous and impractical — mainly for one reason: entering traffic had the right of way, while circulating traffic had to yield. This led to high-speed merging and over-congestion which, in turn, increased the frequency of collisions.
Revamped in the 1960’s, modern roundabouts now give priority to circulating vehicles making them much safer than their circulatory roadway ancestors. These modern roundabouts weren’t built in the U.S. until the late 1990’s. We now maintain about 90 roundabouts per 100,000 miles of paved road in the U.S. (The UK boasts not only the most roundabouts in the world – as a proportion of total road space – they also maintain a “ Roundabout Appreciation Society”, whose president is known locally as The Lord of the Rings.)
Using simple principles of physics, roundabouts dramatically reduce crash rates, as well as injuries and deaths. They diminish vehicle emissions. They are a more effective use of road space, and cost less to maintain than traditional four-way intersections. Roundabouts reduce crashes by the very nature of their geometry. While traditional four-way intersections have 32 possible collision conflict points, roundabouts have only 8. In 2001, Discover Magazine declared: “The roundabout is the single most important device ever created to help control traffic safely and smoothly.”