Systemic approach to revamp unsignalized intersections using multi-criteria decision making: a comparison of alternative solutions

Unsignalized intersections in urban areas require revamping when traffic volume becomes high or movement is unsafe. In developing countries, due to heavy land use and unplanned growth of cities, road extension is not feasible. So, the performance of unsignalized intersections has to be improved by utilizing the available road space optimally. This study proposes a methodology to revamp isolated unsignalized intersections in congested urban areas by comparing the performance of four space efficient alternative solutions – Mini Roundabout, Speed Hump, Right Turn Short Lane, and Median U-Turn. The best solution was decided based on multi-criteria decision making to make a holistic improvement in intersection performance. Four performance criteria were considered – flow, average delay, safety, and vehicular emission. VISSIM is used to simulate two isolated unsignalized intersections, and then the network characteristics of the proposed alternative solutions are configured to test their performances based on the four chosen criteria. Multi-criteria decision making approach has shown that mini roundabout is the most suitable design to improve the performance of isolated unsignalized intersections.