Strategies for Effective Roundabout Speed Reduction

Appropriate deceleration on approaches to roundabouts is primarily accomplished through the use of applicable geometric design principles. However, traffic control devices (specifically signing and makings on approach) also serve a vital role in communicating to the approaching driver what speed profile should be anticipated. This report provides a resource for engineers to identify and select appropriate speed-reduction treatments for high- speed approaches to roundabouts. The research examines best practices and techniques that are the most effective at lowering approach speed.