Assessing Pedestrian and Bicycle Safety in Modern Roundabouts within Cold Region Environments

Abstract: Modern roundabouts have been increasingly implemented as a preferred intersection design due to their ability to improve traffic flow and reduce the frequency and severity of crashes. However, the safety performance of roundabouts for non-motorized users—specifically pedestrians and bicyclists—remains a critical area of investigation, especially in cold region environments where weather conditions can further complicate traffic dynamics.

This study focuses on assessing pedestrian and bicycle safety in modern roundabouts within cold regions, using Minnesota as a representative case study. Minnesota was chosen due to its extensive roundabout implementation and the scarcity of comprehensive data from other cold regions. The study's objective is to identify the unique challenges faced by pedestrians and bicyclists in these environments and to provide actionable insights that can guide future roundabout designs and policies.

The research employs a multi-faceted approach, combining empirical data from case studies, statistical analyses, and simulation models. This approach allows for a thorough examination of how specific design features—such as roundabout geometry, signalization, right-of-way assignments, and sensory cues—affect pedestrian and bicycle safety. The study also considers the impact of cold region-specific factors, including snow accumulation, ice formation, and reduced visibility, which are known to influence both driver and pedestrian behavior.

Key findings from the statistical analysis indicate that while roundabouts generally exhibit higher overall crash rates for pedestrians and bicyclists compared to all-way and thru-stop-controlled intersections, they are significantly more effective in reducing the severity of crashes. Specifically, the research found that roundabouts are associated with a marked reduction in fatal and serious injury crashes for non-motorized users. This reduction is attributed to the inherent design of roundabouts, which slows down traffic and reduces the number of conflict points where crashes are likely to occur.

Despite these benefits, the higher frequency of minor incidents suggests that additional measures are necessary to further enhance safety. The study recommends design adjustments such as the installation of more visible crosswalks, improved signage, and the use of pedestrian-activated signals, particularly in regions with severe winter conditions. These measures could help address the specific challenges posed by cold region environments, such as reduced stopping distances due to icy roads and the limited visibility caused by snow and darkness.

Moreover, the study emphasizes the importance of public education campaigns aimed at improving the understanding of how to navigate roundabouts safely, both for drivers and non-motorized users. Educating the public on the correct usage of roundabouts, including yielding behavior and crosswalk usage, is crucial for maximizing the safety benefits of these intersections.

Overall, this research contributes to the growing body of knowledge on roundabout safety, particularly in cold regions where the challenges are unique and under-explored. The findings provide valuable insights for urban planners, transportation engineers, and policymakers tasked with designing and maintaining safe and efficient transportation infrastructure in cold climates. By addressing the specific needs of pedestrians and bicyclists in these environments, the study aims to enhance the overall safety and functionality of modern roundabouts.