‘Roundabouts’ help improve traffic

Back in my architectural student days I had two professors, both English and one a city planner, constantly talking about “roundabouts.”Roundabouts? I learned they were an English term for what we Americans called rotaries or traffic circles. In the U.S. hardly any had been built since before the War whereas in England they were rediscovered in the late 1950s and updated, improved variations were being designed and constructed by architects, landscape architects, city planners and traffic engineers throughout Great Britain. In addition to rebuilding war-torn urban areas, Britain had also embarked on a program of constructing a series of new towns, and designers tried to employ the most advanced techniques including roundabouts.

Within a few years other European countries started to follow suit; and several others began intensively rebuilding. France, Italy, Sweden, Germany, the Netherlands and several other countries began major road building campaigns, all of which featured new roundabouts.

A roundabout (or rotary or traffic circle) is a type of traffic intersection in which traffic travels in one direction around a central island; priority is given to the circulating flow. Signs usually direct traffic entering the circle to slow and to give way to traffic already on it.

Roundabouts have several advantages over ordinary intersections. They are much safer with many fewer places where crashes might occur. A study of five roundabouts by the Connecticut Department of Transportation found an 81% reduction in severe crashes and a 44 % reduction in total crashes. Driving speeds are reduced and the basic geometry rules out the possibility of any head on or T-bone crashes. Vehicles (nearly always) enter and exit without completely stopping thus reducing noise, pollution, and fuel consumption. The cost of construction of a roundabout is balanced against that of installing and maintaining sophisticated traffic lights, signs and signals.

Roundabouts do have a few disadvantages. Large, high traffic installations may need a lot of space to function ideally and to look right in their place in the landscape. Some of the largest, multi-lane roundabouts may be confusing for some drivers leading to hesitation or incorrect lane use; however, this confusion is over after one or two encounters for most drivers.

Older traffic circles such as Columbus Circle in Manhattan (1904) are not considered by modern traffic designers as roundabouts (they’re just thought of as traffic circles) .

An older, small traffic circle with which readers are familiar is the one at the intersection of Routes 4 and 63 in Goshen.A precursor to the large modern roundabout, although much smaller, it functions much like its contemporary cousins moving traffic smoothly and efficiently. But plans are underway to convert the Goshen traffic circle into a much larger, carefully planted roundabout with a pedestrian crosswalk.

After years of community conflict, the intersection of Routes 7 and 41 at the south end of Great Barrington was finally converted into a roundabout. Construction faced political delay for years; only after it was built and local citizens got used to it did it become accepted, even popular.

Most estimates for the number of roundabouts in the U.S. today indicate there are more than 13,000.In Connecticut there are only about 30, but many more are in the works.Carmel, Indiana a city of roughly 100,000 people, has an astonishing record number of roundabouts, more than 150! Apparently, the city’s mayor and many of its citizens fell in love with roundabouts and kept converting more and more intersections.

Roundabouts have become popular all over the world, especially in Europe (which tends to be more congested than North America). France has the largest number: more than 43,000.And in poorer developing countries with fewer motor vehicles but exploding populations the roundabout boom is only just beginning.

More and more, architects, landscape architects and other artists are getting into the act, right from the beginning to turn these constructions into actual art works, something usually overlooked in the past. The center islands were often the obvious place to start with huge sculptures. But more attention is now being paid to all of the surrounding landscape. This could be a route to a really improved segment of our public space.

Architect and landscape designer Mac Gordon lives in Lakeville.