Abstract: Road traffic accidents represent a major threat to public safety and socio-economic development, with severe accidents causing particularly significant losses of life and property. Based on traffic accident data collected in a specific region from 2017–2020, this study employed random forest sensitivity analysis combined with statistical methods to identify and examine the key factors influencing accident severity. The results indicate that lighting conditions, casualty type, driving experience, intersection type, lane or median configuration, and pavement type are the core variables. Further analysis revealed that severe accidents predominantly occurred during daytime and well-lit nighttime hours, with drivers and passengers of moderate driving experience (5–10 years) exhibiting higher risk profiles. Sections without intersections or Y-shaped intersections demonstrated particularly prominent risks, while the most critical hazards were identified in unseparated two-way lanes. The findings highlight that both roadway design and participant characteristics play decisive roles in accident severity, providing a scientific basis for traffic safety management and risk prevention.

Key words: severe traffic accidents; key influencing factors; influence mechanisms; traffic safety; risk prevention and control

摘要： 道路交通事故是影响公共安全和社会经济发展的重要因素，其中严重事故造成的生命 与财产损失尤为巨大。文章基于某地区 2017－2020 年交通事故数据，采用随机森林敏感性分 析与统计方法识别并探讨事故严重程度的关键影响因素。结果表明，光照条件、伤亡者类别、 驾驶经验、路口类型、车道或中央隔离带设置及路面类型是核心变量。进一步分析发现，严 重事故多发生在白天和照明良好的夜间，中等驾龄（5－10 年）驾驶员与骑乘人员群体风险 较高，无交叉口及 Y 型交叉口路段风险突出，而无隔离的双向车道隐患最为严重。研究表明， 道路环境设计与交通参与者特征对事故严重性具有重要作用，为交通安全管理与风险防控提 供了科学依据。

关键词: 严重交通事故；主要影响因素；影响机制；交通安全；风险防控