Under some circumstances, roundabouts offer many advantages over other intersection control options: fewer vehicle accidents, higher capacity, reduced maintenance costs, better appearance, and increased pedestrian safety. For example, in foreign countries where the use of roundabouts is well-established, traffic engineers almost always choose roundabouts in situations where U.S. engineers would choose all-way stop controls: all-way stop control is virtually nonexistent in these countries. This course provides information and guidance on roundabouts and is intended to help engineers and planners identify situations where roundabouts should be used and what kind of roundabout should be selected. The material contained in the course has been developed with input from transportation practitioners and researchers from around the world. Topics: Defining physical features and key dimensions Distinguishing roundabouts from other circular intersections Multimodal considerations Costs associated with roundabouts Legal considerations Public involvement and education in the use of roundabouts Planning steps for implementing roundabouts Determining number of entry lanes Types of roundabouts from which to choose Comparing operational performance of alternatives Space requirements