The U.S. developed the first rotary traffic circle in 1904 at Columbus Circle in New York City. No right-of-way rules were established, and although an improvement over the previous intersection control, the circle would lock up under heavier volumes and required police control during peak hours. Several initially prominent U.S. traffic circles were either replaced by interchanges or had signals added within the circle, and by the 1950s, these traffic circles had generally fallen out of favor in the U.S.

At about that same time, British traffic engineers began evaluating operations of what today termed "Modern Roundabouts" (Roundabouts are today most often discussed as being different from traffic circles. There are specific design considerations/criteria which separate them. These start with flare on entry and deflection to reduce through speeds). British experimentation and evaluation of the Modern Roundabout showed the design to have higher capacities when a "priority-to-the-circle" rule was applied. Roundabouts design evolved with smaller diameters and wider entry points, resulting in 10 to 50 percent increases in capacity. Despite the proliferation of Modern Roundabout designs abroad, they have only recently been more widely implemented in the U.S. The first modern Roundabouts in the U.S. were designed in Summerland (Las Vegas), Nevada in 1992, and others followed in Gainesville, Florida and Avon, Colorado.