With the rapid expansion of personal mobility (PM) devices as urban transport alternatives, the associated safety risks have increased significantly. Although previous studies have offered insights into user behavior and accident traits, more integrated approaches that consider spatial and administrative contexts are required to better understand the factors affecting accident severity. This study investigated the factors influencing accident severity involving PM devices in Seoul, South Korea by employing a cross-classified multilevel model (CCMM) to account for both police jurisdiction and regional characteristics. Analyzing the 2021 data from the Traffic Accident Analysis System (TAAS), the model showed strong validity (ICC: 15.8%, DIC: 697.2), outperforming the logistic and hierarchical models. Key predictors of higher severity included crashes in non-standard areas (e.g., other than single roads or intersections), helmet non-use, and older age of victims and perpetrators. Violations, such as exceeding passenger capacity, were negatively associated with severity. Industrial areas and high subway station densities reduced the severity, reflecting the benefits of pedestrian-friendly infrastructure. Larger areas covered by police officers significantly increased the severity, revealing enforcement limitations. The 2021 Road Traffic Act revision has had no statistically significant impact. These results highlight the need for integrated policies that combine infrastructure improvements, enhanced enforcement, and behavioral changes to reduce the severity of PM-related accidents in urban environments.

ABSTRACT
1. 서론
    1.1. 연구배경 및 목적
    1.2. 연구의 방법 및 구성
2. 이론적 배경 및 선행연구 검토
    2.1. 개인형 이동장치 관련 사고 연구
    2.2. 교차분류 다층모형 관련 연구
    2.3. 선행연구의 한계 및 본 연구의 필요성
3. 분석 자료 및 변수 구성
    3.1. 자료 수집 및 전처리 절차
    3.2. 사고심각도 분석을 위한 변수 정의
4. 분석 방법론
    4.1. 전체 분석 절차 개요
    4.2. 로지스틱 회귀분석 모형
    4.3. 위계적 로지스틱 모형
    4.4. 교차분류 다층모형
5. 모형구축 및 분석결과
    5.1. 모형구축 결과
    5.2. 사고수준(Level1) 변수의 사고심각도 영향 분석
    5.3. 상위 수준(Level2) 변수의 사고심각도 영향 분석
6. 정책적 시사점
7. 결론 및 향후 연구 과제
감사의 글
REFERENCES

• 이명섭(명지대학교 교통공학과 박사과정) | Lee Myoung-sub
• 박호철(명지대학교 교통공학과 부교수) | Park Ho-chul
• 맹기영(명지대학교 교통공학과 박사과정) | Maeng Giyoung
• 이재영(경찰청 경찰인재개발원 교통안전교육센터 경감, 공학박사) | Lee Jae-yeong Corresponding author