Abstract: To study the roadway intersection, traffic conflict technology is introduced to quantitative analysis of traffic safety, it is proposed that different severities of traffic conflict cause different traffic safety results. The paper analyzes the characteristics of traffic flow at intersection and the severity of different types of traffic conflicts, and researches the angle, deceleration and kinetic energy loss of turning vehicle based on physics collision theory. The relations and models of crossing traffic conflict, diverge conflict and merge conflict after collision are developed. Traffic conflict unit index is developed according to the probability of three traffic conflict types and the level of serious when collision occurs. Finally, the research combine all results for establishing useful indexes of intersection safety, and it is very important to focus such issues by traffic engineers.

Key words: urban traffic, traffic conflict unit, traffic safety, collision theory, severity of traffic conflict

摘要： 以道路平面交叉口为研究对象，引入交通冲突技术定量分析道路交通安全状况，提出应考虑不同类型的交通冲突其严重性不同，对交通安全的影响也不同. 通过对平面交叉口交通车流的分析以及对不同类型交通冲突的严重性研究，基于物理碰撞学的理论，利用转向车辆的角度变化及减速关系，以车辆碰撞后的动能损失量，推导出交叉冲突、合流冲突和分流冲突在交叉路口发生碰撞后严重程度的相互权重关系，建立了此三种类型的关系模型. 并在分析交通冲突发生概率及碰撞后的严重程度基础上，引入了当量交通冲突数概念，作为评价交叉路口安全性的指标，以提供交通工程师评估路口安全性的依据.

关键词: 城市交通, 当量交通冲突量, 交通安全, 碰撞理论, 冲突严重性