Influencing Factors in Personal Mobility Device Accident Severity in Korea

Personal Mobility Devices (PMDs), also known as micromobility devices, have expanded rapidly in Korea, accompanied by a sharp increase in accidents and severe injuries. Using six years of nationwide PMD accident data, this study applies a decision tree approach to identify key factors and their non-linear interactions across human, environmental, and accident-related variables. The results show that accident type is the most influential factor, followed by rider age and gross negligence. PMD-only accidents, although the least frequent, exhibit the highest fatality risk, particularly among older riders and unlicensed young riders. PMD-to-vehicle accidents are the most common, with higher fatality risks observed in head-on crashes and turning maneuvers involving older riders, while younger riders face greater risks at large intersections. PMD-to-pedestrian accidents show the lowest fatality rate but greater severity when gross negligence is involved. These findings highlight the need for targeted training, infrastructure improvements, and policy measures to enhance PMD safety.