High Speed Approaches at Roundabouts

The rising need of traffic control devices in sprawling suburban and rural areas, which are predominantly connected by higher speed roadways, as well as the rising awareness of the benefits of modern roundabouts has raised the common question in North America of whether roundabouts are appropriate at intersections with high speed approaches. This report identifies and evaluates the perceived concern of placing modern roundabouts on roadways or corridors with high-speed approaches (45 miles per hour or greater). The report takes an engineering standpoint of analyzing several roundabout case studies with high speed approaches found in North America. In short, this report answers the question of whether modern roundabouts are appropriate at intersections with high-speed approaches based on safety research. It also provides recommendations and elements of design for high-speed conditions that are crucial to the safety performance of modern roundabouts.