Roundabouts are a road design used to replace a traditional four or six-way intersection, referred to as a crossroads intersection, with a circular path around which traffic flows, continuously, in one direction. The graphic provides an overview of such a roundabout.

For a driver not accustomed to this sort of intersection, a roundabout may be disconcerting at first. However, study after study shows that in the right locations roundabouts are an improvement over more traditional crossroad intersections in two ways: by increasing the flow of traffic and by reducing (by 76%) the number of injury-producing accidents. The reduction in accidents leading to fatalities in a roundabout versus a crossroad intersection is even greater since speeds are reduced throughout the intersection. According to the U.S. Department of Transportation, there are 90% fewer fatal accidents in crossroads intersections that have been replaced by roundabouts.

Today’s market size is the estimated number of roundabout intersections worldwide, in 1997 and in 2012.

Geographic reference: World
Year: 1997 and 2012
Market size: 35,000 and 60,000 respectively
Source: “The Widening Gyre,” The Economist, October 5, 2013, page 16. The graphic comes from a Michigan Department of Transportation website, here.
Original source: U.S. Department of Transportation
Posted on November 25, 2013