从减少城市交叉口车辆排放的角度出发，根据行驶方向与行驶工况变化对车辆尾气排放的 影响，建立了车辆在直行和左转过程中完全停车、不完全停车以及不停车3 种状态下的机动车综 合排放模型，并将其与延误相结合，提出以车辆延误与排放的综合指标为优化目标，基于等饱和 度优化分解算法对信号周期进行求解的优化控制模型。使用VISSIM 微观交通仿真软件分别对原 有配时、Webster 优化配时和文中提出的综合指标优化配时进行了仿真实验和对比分析。结果表 明，采用文中算法优化的配时在交叉口总延误时间、总排放量和综合指标PI 方面都明显减少，优 化效果显著。

From the aspect of reducing the vehicle emission in urban intersection, according to the ef⁃ fect of driving direction and condition on vehicle emission, vehicle emission comprehensive model, in⁃ cluding vehicle states of complete parking, incomplete parking and no parking under the condition of go⁃ ing straight and turning left, was established. Combined with vehicle delay, a optimization control model was proposed taking delay and emission as optimization objects and equal saturation optimization decom⁃ position algorithm as solving method of cycle length. VISSIM simulation software was utilized to simu⁃ late, compare, and analyze the original timing, the Webster optimization timing and the comprehensive index optimization timing. Simulation result shows that the proposed method can obviously decrease the total delay, total emission and comprehensive index PI, and it has obvious optimization effect.