Going Around the Neighborhood – A Roundabout Case Study in Texas

This paper describes a neighborhood traffic management study that was conducted in a suburban Dallas, Texas community. The purpose of the study was to attempt the reduction in cut-through traffic. Traffic calming measures were originally evaluated as part of the study; however, a closer analysis of the existing conditions in the field revealed that improvements to an intersection adjacent to the neighborhood could potentially solve the problem. This arterial-collector intersection experienced long delays and excessive queue lengths under all-way stop control during the peak periods, leading to a considerable amount of cut-through traffic on the study neighborhood roadways. Possible improvements to this intersection (additional lanes/signalization/roundabout) were evaluated by Lee Engineering and the City of Southlake before proceeding with the first roundabout in the community. A single-lane urban roundabout constructed within the existing right-of-way was predicted to increase mobility at the intersection and reduce cut-through traffic in the neighborhood. Traffic data collected before and after the installation of the roundabout indicated a reduction in delay, a reduction in queue lengths, and an increase in entering traffic volumes. Additionally, the roundabout eliminated complaints of cut-through traffic through the neighborhood.