Modem roundabouts are being installed on state and local roads in the United States at an increasing rate. Roundabouts can be less expensive to construct and operate than signalized intersections, and their use reduces vehicle delay, while enhancing the aesthetic appeal of the surrounding community. However, while most guides suggest that roundabouts should improve older driver safety, the ability of older drivers and pedestrians to successfully navigate roundabouts has not been thoroughly investigated. A brief literature review has shown that, while researchers are beginning to explore the effects of roundabouts on crash rates and severity in the U.S., little research has looked at the effect of age on those measures. The proposed research aims to examine the following: (1) the growth in modem roundabouts in the state of Florida, including the proximity of roundabouts to communities with high numbers of older adults; and (2) crash rates and severity of roundabout crashes involving older drivers and pedestrians. The study will generate important baseline knowledge on potential problem areas and form the basis for additional interdisciplinary research within the Center, including simulator studies to examine older drivers' and pedestrians' comfort with and level of success navigating roundabouts.