There is an increasing interest in using microsimulation models for traffic safety evaluations and several calibration procedures were proposed for the simulation models to obtain a high correlation between the simulated and field-measured conflicts. However, since the ultimate goal of safety studies is to reduce crashes, the simulation model needs to be calibrated to ensure an accurate prediction of crashes. The objective of this study is to propose an innovative calibration approach for microsimulation models using the extreme value theory (EVT) approach. The EVT approach was shown to connect non-crash events to crashes, providing reasonable crash estimates from traffic conflicts. The goal of the proposed calibration process is to produce an extreme value distribution of simulated conflicts that matches the one of field-measured conflicts. A Genetic algorithm is utilized to obtain VISSIM model parameters that can achieve this goal. Traffic video data collected from two approaches at a signalized intersection in Surrey, Canada were used as case studies. Automated traffic conflicts analysis techniques were used to extract field-measured conflicts. Simulated conflicts were extracted from vehicle trajectories from VISSIM using the surrogate safety assessment model (SSAM) tool. EVT models were developed to estimate the generalized Pareto (GP) distributions of both field-measured conflicts and simulated conflicts of different scenarios. The calibration results show considerable matching of the estimated GP distributions between simulated conflicts and field-measured conflicts. As such, the proposed calibration procedure for microsimulation model is recommended as a promising approach in simulation-based safety evaluation of signalized intersections.

使用微观模拟模型进行交通安全评估的兴趣日益浓厚，针对模拟模型提出了几种校准程序，以在模拟冲突和实测冲突之间获得高度相关性。但是，由于安全研究的最终目标是减少碰撞，因此需要对仿真模型进行校准以确保对碰撞的准确预测。这项研究的目的是使用极值理论（EVT）方法为微仿真模型提出一种创新的校准方法。事实证明，EVT方法可将非崩溃事件与崩溃联系起来，从而根据交通冲突提供合理的崩溃估计。提出的校准过程的目标是产生与现场测量的冲突之一匹配的模拟冲突的极值分布。利用遗传算法获得可以实现该目标的VISSIM模型参数。从加拿大萨里信号交叉口的两种方法收集的交通视频数据用作案例研究。自动交通冲突分析技术用于提取现场测量的冲突。使用替代安全评估模型（SSAM）工具从VISSIM的车辆轨迹中提取了模拟的冲突。开发了EVT模型以估计不同情况下现场测量的冲突和模拟冲突的广义Pareto（GP）分布。校准结果表明，模拟冲突和实测冲突之间的估计GP分布相当匹配。因此，