Evaluating the Conversion of All-Way Stop-Controlled Intersections into Roundabouts

Roundabouts are becoming increasingly popular in the United States and have been considered for use at intersections facing operational or safety problems. A comparative analysis was performed on all-way stop-controlled (AWSC) intersections and roundabouts on the basis of aaSIDRA software after calibration against local conditions in Delaware and Maryland. A decision support system was developed in the form of a knowledge-based expert system on the basis of the results of the analysis to evaluate the performance of AWSC intersections and their potential success if converted into roundabouts. The results of the comparative analysis are in line with some previous researchers’ findings that AWSC intersections always perform worse than signal-controlled or roundabout type intersections under the same set of traffic conditions and geometric limitations.