A Systematic Review of Proactive Roundabout Safety Assessment Methods using Surrogate Safety Measures

The present study aims to understand potential challenges at roundabouts through a proactive, data-driven approach. A systematic review was conducted following PRISMA guidelines, focusing on existing literature that assesses roundabout safety using surrogate safety measures. A total of twenty-three studies were selected for the final review, emphasizing conflict analysis, assessment methodologies, and severity evaluation based on critical thresholds identified in prior research. The review also examined various validation approaches employed to ensure the reliability of safety models.
Findings highlight that roundabout geometry significantly influences conflict frequency and severity. Variations in safety indicator thresholds were observed, often linked to geometric design, traffic volumes, and local traffic conditions. Additionally, the review identified gaps in validation methodologies, with many studies lacking robust model validation.
This study contributes to a deeper understanding of roundabout safety, offering insights into user interactions, conflict types, and key safety indicators. Furthermore, the study explores threshold selection and the importance of validation techniques. Addressing these gaps will strengthen safety evaluation practices and support more informed, data-backed policy decisions and design improvements for safer roundabouts.