Operational Performance of Kansas Roundabouts: Phase II

Modern roundabouts are being implemented throughout the United States (US) in a variety of locations. Single-lane roundabouts may perform better than two-way stop-controlled intersections in the US under some conditions. The safety record of well designed modern roundabouts is excellent. The primary objective of this study was to compare the operational performance of 11 modern roundabouts in Kansas with other intersection traffic control devices in five locations in Kansas. This study found that there were statistically significant reductions in delay, queuing, and proportion of vehicles stopped at all the study sites after the installation of a modern roundabout. It is reasonable to suggest that the movement of traffic through these intersections should be significantly improved and a modern roundabout should be the best intersection alternative for several other locations in Kansas with similar traffic volumes and similar geometrics. Further studies should be conducted in other locations in Kansas with different traffic conditions and geometrics, particularly those where volumes are high enough that a multi-lane roundabout is required, in order to get a clearer picture.