Roundabout or traffic signal: a selection dilemma

Abstract

At-grade intersections are one of the vital elements in any road network. Traffic control for at-grade intersections plays a significant role in the level of delay experienced by the vehicles on the road network. Traffic signals and roundabout control are the most common types of at-grade intersection control. Many transportation planners around the world debate the selection between these two types of control for a new at-grade intersection. The aim of this research is to provide some guidelines for selecting one of the two types of control for some at-grade intersections. The research utilized the well-known software packages of Synchro and Sidra to evaluate the performance of traffic signals and roundabouts, respectively. The experimental work considered a four leg at-grade intersection that was operated under different traffic congestion levels and different traffic distribution percentages. The research results indicated that roundabouts are recommended for small traffic volumes while traffic signals are proven to be more suitable for high traffic volumes.