Safety evaluation of Czech roundabouts

Roundabouts around the world are often seen as a beneficial measure for intersection safety. Although their number has grown recently in the Czech Republic, their safety impact has not been fully studied. Furthermore, Czech roundabouts have sometimes been unpopular, including doubts about their benefits. This situation inspired the authors to investigate three questions related to Czech roundabouts: (1) Are roundabouts safer than traditional intersections?; (2) Are roundabout conversions beneficial for safety?; (3) Is Czech roundabout safety performance comparable to other countries? Safety performance functions were developed based on data samples and used in order to answer these research questions. The final results are mixed: roundabouts seem to be safer compared to traditional intersections and before-after study of urban roundabout conversions yielded positive crash modification factors; on the other hand, expected crash frequencies on Czech roundabouts are higher compared to other European countries.