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.

Summary presentations of the database that include estimates of roundabouts in the United States and Canada (including estimated unknown sites) can be found here:

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