为有效地评估高速公路现有或预建入口匝道合流区的交通安全性，提出了一种综合考虑冲突概率 (CP) 与冲突严重性 (CS) 的 CP-CS 融合模型。首先，考虑车辆微观运行特征对交通冲突的影响，构建了冲突概率模型; 然后，利用统计数据集成冲突概率与冲突严重性，建立了 CP-CS 融合模型; 最后，结合实测交通数据，采用 SSAM 交通冲突仿真分析验证所建模型的有效性，并基于案例研究揭示合流区风险系数演变机理，明确不同优化方案下合流区的安全状态。实验结果表明: 文中模型有助于提高现有或预建入口匝道的安全水平; 当主线车流速度小于 27 m /s，每小时流量低于 1 000 辆时，合流区具有较高的通行效率与安全水平。

A CP-CS fusion model that considers both conflict probability ( CP) and conflict severity ( CS) was pro- posed to effectively evaluate the traffic safety of existing or pre-built on-ramp merging areas on the highway． Firstly， the conflict probability model was established considering the impact of vehicle micro-running characteristics on traffic conflicts． Furthermore，the statistical data were used to integrate the conflict probability and conflict severity，so as to construct the CP-CS fusion model． Finally，based on the observation data，SSAM traffic conflict simulation analysis was carried out to verify the effectiveness of the proposed model． Moreover，a case study was introduced to reveal the evolution mechanism of risk coefficients in the merging areas，and illustrate the safety level of the merging areas under various optimization schemes． The experimental results show that the proposed model can improve the safety level of the existing or pre-built on-ramp． And there is a relatively higher traffic efficiency and safety level in the merging areas when the speed of traffic flow on the mainline is smaller than 27 m /s and the traffic flow is less than 1000 veh /h．