为了得到山地城市信号交叉口通行能力影响因素中进口道坡度的修正系数，明确其对饱和 流量的影响，在实际交通环境中难以获得理想条件的情况下，基于VISSIM 设置了仿真环境。根 据山地城市交通流特点对仿真参数进行了校正，在此基础上设计了不同进口道坡度下饱和流量仿 真实验，根据仿真实验数据分别建立了坡度为正、负情况下影响饱和流量的进口道坡度修正系数 模型。实验结果表明，上坡时2%的坡度对饱和流量开始产生较明显的影响，10%以上的坡度影 响开始减弱；下坡时-3%的坡度对饱和流量开始产生较明显的影响，-7%以下的坡度影响开始减 弱。最后利用实测数据对比HCM法，验证了模型在我国的适用性。

In order to analyze the effect of approach grade on saturation flow at signalized intersection and get the adjustment factor for approach grade, traffic situation was simulated by VISSIM because the ideal situation was unobtainable in real situation. The simulation parameters were calibrated based on ac⁃ tual traffic flows at the mountain cities. The simulation tests about the effect of different approach grades on the saturation flow were designed and the adjustment factor models for approach upgrade and down⁃ grade were provided. The results show that an upgrade 2% begins to effect the saturation flow obviously and the effects start to weaken above 10% upgrade. A downgrade -3% begins to effect the saturation flow obviously and the effects start to weaken below -7% downgrade. Finally, a comparison of the recom⁃ mended methods to HCM methods based on measured data validates the applicabilities of that the rec⁃ ommended methods in China.