Current international research shows that modern roundabouts improve vehicular and pedestrian safety compared to conventional intersections. However, their effects on pedestrian safety in the U.S. remain unsubstantiated. Complicating this problem is a scarcity of pedestrian accident data at roundabouts, especially at intersection locations that were reconstructed as roundabouts and could potentially provide critical before/after accident statistics. This research seeks to examine the safety issues by summarizing the literature that describes international and U.S. experience with roundabouts and pedestrian safety. The research applies three alternate approaches to assess pedestrian safety at roundabouts: case study analysis, statistical analysis, and simulation analysis to compare pedestrian safety at a conventional signalised intersection to a case study modern roundabout. The case study focuses on a proposed roundabout location - the Hillsborough-Horne Street intersection at North Carolina State University (NCSU) in Raleigh, North Carolina. It is scheduled for reconstruction as a roundabout as part of a corridor project to improve the "front door" to NCSU, as well as improve pedestrian safety. First, pedestrian accident histories for the intersection, which has the fourth highest frequency of pedestrian accidents in North Carolina, are examined with and without the proposed roundabout. Based on reduced vehicle-pedestrian conflicts and better control of wrong-way movements, the proposed roundabout shows promise. Second, a regression model for pedestrian accidents versus street and intersection characteristics of a one-mile section of Hillsborough Street is developed. If a roundabout were constructed, the model forecasts a reduction in pedestrian accidents. Third, a simulation analysis of the Hillsborough-Horne intersection shows that the planned roundabout would have equivalent pedestrian capacity and potentially better pedestrian safety than the original signalised intersection. In summary, the three independent approaches suggest that a roundabout design will improve pedestrian safety at the case study intersection. (Author/publisher)
Abstract