Modern Roundabouts - the Web Site Welcome to the Modern Roundabouts Web site. This Web site serves as one of the definitive sources on Modern Roundabouts and is a complement to a Federal Highway Administration research project aimed at developing a comprehensive guide to roundabouts design.
Roundabouts are a common form of intersection control used throughout the world.
However, many state and local agencies throughout the United States have been hesitant to install roundabouts due to a lack of objective nationwide guidelines on planning, performance, and design of roundabouts. Prior to the development of this guide, the few state and local agencies interested in roundabouts had to rely on foreign roundabout design guides, roundabout proponents, or in some states, statewide roundabout design guides. Roundabouts require strict conformance to standard practice to ensure safe, optimal operation, and this scattered approach to design can lead to inconsistencies at a national level which are consequential in terms of driver expectation and safety. You can search the current records in the database or add new sites that are not yet listed. An outline of the comprehensive national Roundabout Design Guide currently being developed.