Safety Impacts of Access Management Features near Roundabouts

Roundabouts can better facilitate U-turns and provide better safety, especially in reducing severe crashes, than can traditional intersections. Roundabouts, instead of traditional signalized intersections, increasingly are being installed on busy arterial streets. Even though roundabouts gradually are becoming integral to regional transportation networks, no literature addresses the safety impacts of access management features such as driveways and median openings along corridors with roundabouts. The existing access management guidelines for signalized intersections are not directly applicable to roundabouts because traffic operations are different at the two types of intersections. In this study the safety impact of access features near roundabouts was investigated. In particular, three potential safety concerns associated with roundabouts were studied in commercial areas in Florida: (a) the impact of driveway corner clearances on roundabout safety, (b) the safety impact of median openings near roundabouts, and (c) the safety at roundabouts that provided direct access to activity centers. Data for the analysis reflected 131 roundabouts in commercial areas in Florida. Police reports for more than 1,000 crashes that occurred in roundabout influence areas between 2007 and 2011 were reviewed carefully to identify crash patterns and causes related to specific roundabout designs, con-figurations, and access features. Recommendations are made for access features near roundabouts in commercial areas.