New England Rotaries are closer to roundabouts than traffic circles, but not generally considered the same. "Most common in the New England region of the Unite

New England Rotaries are closer to roundabouts than traffic circles, but not generally considered the same. "Most common in the New England region of the United States, a rotary is primarily a mid 20th century roadway design defined as a circular, one way, often multi-lane roadway, similar to a traffic circle or a roundabout, but with key differences. They are often found as overpasses or underpasses to highways. Usually traffic already in the rotary has the right-of-way as in a modern roundabout and opposite of a traffic circle, although there are exceptions. The difference in design of a rotary versus a roundabout or a traffic circle, is such that rotaries tend to be quite large and there is little deflection around the central circle (meaning traffic coming on or off does so primarily in a straight line, not a curve). These two factors mean that rotary traffic often travels at speeds in excess of 30 miles per hour, leading to confusion and accidents, and the resulting unpopularity, that the modern roundabout does not suffer from. Although this is a traffic engineering definition, many rotaries are called traffic circles or simply circles, such as the Portsmouth Traffic Circle, in naming." http://en.wikipedia.org/wiki/Roundabout http://en.wikipedia.org/wiki/Roundabout