Performance Evaluation of Roundabouts for Traffic Delay and Crash Reductions in Oxford, MS

摘要

The overall objective of this study was to assess the performance of the roundabouts in Oxford with respect to traffic flow, capacity, and safety improvements, and to determine the public perception of roundabouts by means of an opinion survey. Detailed post-roundabout traffic movement volume and crash data were collected and compared with the pre-roundabout data to assess the in-service performance of the roundabouts. Traffic flow microsimulation and capacity analysis methods were used to evaluate performance of the roundabouts. The results of the Oxford roundabout study showed significant improvement in traffic flow, crash reduction, and reduction in vehicle emissions. It was found that the conversion of the intersections to roundabouts improved traffic flow by reducing average delay by 24%, idling time by 77%, and fuel wastage by 56%. Overall vehicle emissions from idling were reduced significantly including 56% in CO2, 80% in VOC, and 77% in CO, NOx, and PM10.