Roundabouts: An Informational Guide

Turner Fairbank Highway Safety Research Center

The following topics are addressed:

  • definition od a roundabout and what distinguishes roundabouts from traffic circles
  • public acceptance and legal issues associated with roundabouts
  • consideration of all user modes, including heavy vehicles, buses, transit, bicycles and pedestrians
  • a methodology for identifying appropriate sites for roundabouts and the range of conditions for which roundabouts offer optimal performance
  • methodologies for estimating roundabout capacity, delays, and queues with reference to the Highway Capacity Manual
  • design principles and guidance on safety and geometric design, with reference with reference to applicable national standards such as the AASHTO Policy on Geometric Design of Highways and Streets
  • guidelines for control features such as signing and pavement markings, with reference to the Manual on Uniform Traffic Control Devices
  • illumination
  • landscaping

The Tech Brief is available for download, while the full document is accessible at the link below.

Filed in: Engineering, Plans and Policies

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