This online inventory database of roundabouts and other circular intersections is voluntarily hosted and maintained by Kittelson & Associates, Inc. since 1999 as a service to the Transportation Research Board’s Committee on Roundabouts. Although the information presented is intended to be comprehensive, it is entirely the product of volunteer contributions, and no warranties or representations are made regarding the completeness or accuracy of the information. Public assistance in identifying missing locations or correcting information within the database is welcome.

For inquiries regarding this website and database, please email roundabouts@kittelson.com.

The most recent summary presentation of this database was prepared for the 2020 TRB International Roundabout Conference in Monterey, California, which has been postponed. This poster can be found here. The previous version presented at a conference was for the 2017 TRB International Roundabout Conference in Green Bay, Wisconsin. It can be found here.

This website was rebuilt in 2016 using ASP.NET Core MVC.