The course begins with the definition of physical features and dimensions. Roundabouts are distinguished from other circular intersections and placed into categories such as mini-roundabouts, urban roundabouts and rural roundabouts. Both single lane and double lane roundabouts are included. Policy considerations are discussed such as multimodal considerations and benefits/costs associated with roundabouts. The planning steps to develop a roundabout are detailed. Areas of concern include number of entry lanes, selection of categories, comparing operations performance of alternative intersection types, space requirements and economic evaluation.
Traffic operation at roundabouts is discussed in terms of capacity and performance analysis. Roundabout safety is discussed in terms of conflicts and crash statistics. Geometric design elements such as design speed, radius and superelevation are defined. Traffic design including signing, pavement marking and illumination are detailed. Landscaping of the central island and splitter islands is discussed.
The course is designed to provide a basic knowledge of Roundabout Design from which a person can use this information in traffic studies and roadway design.