We'd like to start today's post with a linguistic exercise you may have already seen before on the Internet: what do you call the circular intersection of several streets? Depending on where you live in the United States, you may have said anything from turnabout to roundabout, rotary to traffic circle. But while some chalk this up to regional dialects, we wanted to point out today that at least two of these terms are not synonymous but rather two different intersections.
We're talking about roundabouts and traffic circles. Though both intersections are circular in nature and occur at intersections of streets, both have differences that make them unique in their function. Let's take a look.
Just as their name implies, roundabouts are circular intersections that allow traffic to flow freely without the use of signals or stop signs. Drivers are required to gauge gaps in traffic, entering the roundabout when it's safe and exiting onto the desired street.
Roundabouts are typically smaller in diameter than traffic circles though, which forces vehicles to reduce their speed when travelling around the intersection. Though they tend to take up more space than a typical right-angle intersection, some consider them safer because they force drivers to rely on their own awareness of their surroundings to make safe driving decisions. The slower speed through the intersection also reduces the likelihood of serious or fatal injuries as well.
Traffic circles on the other hand are oftentimes designed as larger circular intersections that use traffic signals to control the flow of traffic. Unlike roundabouts, which are designed to slow down traffic, the design of a traffic circle tends to allow vehicles to travel through them at higher speeds. This increases the danger to pedestrians and bicyclists who may suffer more serious injuries in an accident.
Source: The Federal Highway Administration, "Modern Roundabouts: A Safer Choice," Sept. 4, 2014, Accessed June 10, 2015