Roundabouts are one of the most ignored beauties hiding in plain sight. These extraordinary creations are taken for granted every day, but it is time to slow down and truly observe. According to Ralph Waldo Emerson “Adopt the pace of nature: her secret is patience.” In today’s blog, that is exactly what we will be doing. We will discuss the functions of Roundabounds; I guarantee you will learn something worth sharing and appreciating for many years.



Definition.

A roundabout is a physical layout where a number of approach roads join a circulating one-way carriageway, on which all traffic flows in the same direction of rotation about the central island.

Roundabouts serve a multitude of functions such as:

1. Traffic Safety

According to the Insurance Institute of Highway Safety (IIHS) article: Public Opinion, Traffic Performance, the Environment, and Safety after the Construction of Double-Lane Roundabouts, “Studies of intersections in Europe and Australia that were converted to roundabouts reported 36-61% reductions in crashes of all severities and 25-87% reductions in injury crashes (2). The safety benefit was greater for small- and medium-capacity roundabouts than for large or multi-lane roundabouts. U.S. studies have shown that conversion of traffic signal- or stop sign-controlled intersections to roundabouts reduced injury crashes by 75-84% and all crashes by 35-40% .”

2. Smoother transitions.

Roundabouts eliminate the necessity of stopping even for crossing streams of vehicles. Roundabouts allow for a constant flow by allowing all vehicles to merge into streams around the roundabout and then to diverge out to the desired radiating road.

3. Aesthetics.

According to the Federal Highway Administration Office of Safety, ‘Technical Summary‘, The central island and splitter islands offer the opportunity to provide attractive entries or centerpieces to communities through use of landscaping, monuments, and art, provided that they are appropriate for the speed environment in which the roundabout is located.

4. Operations and Maintenance.

As reported by the Federal Highway Administration Office of Safety, Technical Summary, “A roundabout typically has lower operating and maintenance costs than a traffic signal due to the lack of technical hardware, signal timing equipment, and electricity needs. Roundabouts also provide substantial cost savings to society due to the reduction in crashes, particularly fatal and injury crashes, over their service life. As a result, the overall life cycle costs of a roundabout can be significantly less than that of a signalized intersection.”

5. More environmentally-friendly.

According to the Ontario Ministry of Transportation, roundabouts accounts for less idling and air pollution. To reiterate, “Reduced delays mean reduced fuel consumption and improved air quality by reducing emissions.”

References

Federal Highway Administration Office of Safety (2010, February). Roundabouts – FHWA Safety Program. Retrieved from http://safety.fhwa.dot.gov/intersection/roundabouts/fhwasa10006/

Highway Roundabout. (n.d.). Retrieved April 2014, from http://www.mto.gov.on.ca/english/engineering/roundabout/

Insurance Institute for Highway Safety (2013, February). Public Opinion, Traffic Performance, the Environment, and Safety after the Construction of Double-Lane Roundabouts. Retrieved April 2014, from http://www.iihs.org/frontend/iihs/documents/masterfiledocs.ashx?id=2033