The Federal Highway Administration (FHWA) has laid some groundwork to support roundabouts. The agency's new guide, "Roundabouts: an informational guide," aims to be "the definitive source of information related to the planning, operation, design, and configuration of modern roundabouts in the United States."
As FHWA points out, roundabouts have limitations as well as strengths. The guide presents information on both positives and negatives to help engineers and planners make the best decisions about when and how to use roundabouts.
This information comes just in time. "Interest in modern roundabouts has grown as a result of positive international experience," says FHWA's Joe Bared, who directed the project. "Hundreds of research papers are now available, and designs are being copied from the Australians and Europeans." The publication interprets best practices from around the world in light of accepted U.S. design standards.
"Designing roundabouts requires a lot of skill," Bared notes. "It's not high tech, but it takes skill to get the speed right and leave enough room inside the circle for vehicles to maneuver."
This attention is important in boosting roundabout construction — and helping towns and cities reap the benefits. "The more roundabouts, the better," Bared says.