Implementation, Driver Behavior, and Simulation: Issues Related to Roundabouts in Northern New England

Roundabouts are an emerging type of intersection design and a relatively new addition to the transportation system in the United States. This imposes two traffic engineering and research related issues. First, data and research on traffic operations and driver behavior at roundabouts are limited. Although beginning to expand in recent years, the knowledge of roundabout operations has been primarily based on data collected abroad where roundabouts are more common. Moreover, capacity and operational models are inadequate since they are derived primarily from concepts of existing stop-controlled and signalized intersections. Second, some motorists are not as accustomed to the new driving patterns associated with a roundabout. This affects traffic operations, especially at newly constructed roundabouts, but can also impact public acceptance of roundabouts which may result in part from the lack of exposure and driver confusion. The research presented here can be organized into three main objectives that center on: 1) better understanding the difficulty of obtaining public approval of roundabouts in the northeastern region of the United States; 2) developing a more comprehensive typology of driving behavior and actual driver maneuvers at roundabouts based on real world data; and 3) advancing the simulation modeling of roundabouts by incorporating driver behavior that is not currently represented in existing traffic simulation models.