Concrete Pavements in Roundabout Intersections: Case Studies

Over the last several decades, the use of roundabouts—a form of circular intersection in which traffic travels counterclockwise around a central island—has grown considerably in the United States. Roundabouts have been shown to be an effective solution for managing traffic at many intersections, offering improved safety performance, shorter delays and shorter queues, improved speed management, reduced operation costs, and aesthetic value.Various pavement structures can be used in roundabout intersections, including three different concrete pavement types: jointed plain concrete (JPC), continuously reinforced concrete (CRC), and precast concrete (PC). JPC structures are by far the most common concrete pavement type used in roundabout construction, but several recent projects in the U.S. have been built featuring CRC and PC designs. All of these concrete pavement types require competent structural designs and effective construction practices to ensure their long-term performance.This paper presents several case studies featuring each of these three concrete pavement types in roundabout intersections. These case studies include two JPC projects in Nevada, two CRC projects in Texas, and two PC projects in Virginia. All sections were successfully constructed within the last 10 years and are performing satisfactorily. Important design and construction elements for each of these projects are described, along with information on the current condition and performance. A summary of “lessons learned” related key design and construction factors influencing the performance of each concrete pavement type is also presented.