Since the publication of NCHRP Report 672: Roundabouts: An Informational Guide-Second Edition, a significant amount of roundabout research has been conducted. Our nation has also constructed many roundabouts in that time period, providing practical knowledge that has fueled additional research. NCHRP sought a new guide that would bring together the latest in roundabout research, best practices from the field, and advancements in transportation technology.


A Kittelson-led team reviewed the latest existing planning and design guidance at the state and national level, connected with practitioners across the country to learn from their experiences, and conducted additional research, particularly around serving large trucks and designing for bicycles at roundabouts.

The Outcome

A New Go-To Guide for the Planning and Design of Roundabouts

NCHRP Research Report 1043: Guide for Roundabouts supersedes NCHRP Report 672 and presents a performance-based approach to the design of roundabouts. It includes guidance for all roundabouts, including multilane, mini-roundabouts and compact roundabouts. The Guide provides enhanced information on bicycle facilities, pedestrian crossings, traffic control devices, illumination, retrofitting existing roundabouts, and many other aspects of roundabout planning, design, and implementation. It is available to be downloaded here on TRB’s website.




National Cooperative Highway Research Program (NCHRP)


National Research