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 the Federal Highway Administration's research project aimed at developing a comprehensive guide to roundabouts design. The results of this project are contained in the book published by FHWA in August 2000; Roundabouts: An Informational Guide.

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.

Prior to the development of Roundabouts: An Informational 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. To address this national need, the Federal Highway Administration selected a worldwide team of experts to develop Roundabouts: An Informational Guide.

Roundabouts: An Informational Guide addresses the following topics:

The pages of this Web site collect and make available much of the information generated from this FHWA project including: