基于组合赋权-TOPSIS法的城市平面立交交通组织评价研究

Study on Evaluation of Urban Plane Interchange Traffic Organization Based on Combined Weighting-TOPSIS Method

平面立交采用苜蓿叶式立交形式和交通组织方式,即通过在普通平面交叉口的4个角上增设右转匝道和小型环路使其在形式上类似于苜蓿叶式立交,因其工程造价低、交通组织灵活、控制方式简单、通行效率高等特点,成为城市快速路与主干道或主干道与主干道交叉口选型之一。根据平面立交交叉口的几何特征和交通组织特点,以及交叉口运行效率、安全、环境等各方面评价目标,提出了以通行能力、车均延误、交叉口安全度、CO排放、绕行距离5个具体评价指标为主的指标体系。克服多指标评价过程中指标权重偏主观或偏客观的情况,采用组合赋权对TOPSIS法进行优化,构建了组合赋权-TOPSIS法的城市平面立交交通组织评价模型。以太原市西中环辅路与兴华西街平面立交的3种交通组织方式为实例,通过连续工作日交叉口流量流向调查、点样本法延误调查、车头时距和车速调查等获取交通数据,建立了VISSIM交叉口仿真模型,直接或间接得到了各评价指标值。通过提出的组合赋权-TOPSIS法确定了各种方案的优劣性。其计算结果与实际情况较为一致,验证了方法的合理性。该结果可为城市平面立交交通组织方式或采用这种思路进行的区域交通组织方案合理评价提供理论支持。

The plane interchange adopts the form and traffic organization mode of alfalfa leaf interchange, that is, by adding right turn ramps and small loops on the 4 corners of the ordinary grade intersection, it is similar to alfalfa leaf interchange in form. Because of its low engineering cost, flexible traffic organization, simple control mode and high traffic efficiency, it has become one of the selection types of urban freeway and main road or main road and its intersection. According to the geometric characteristics and traffic organization characteristics of plane interchange, and the evaluation objectives of intersection operation efficiency, safety, environment and other aspects, an indicator system based on 5 specific evaluation indicators(traffic capacity, average vehicle delay, intersection safety, CO emission, and detour distance) is proposed. To overcome the subjective or objective situation of the indicator weight in the process of multi-indicator evaluation, the TOPSIS method is optimized by using combined weighting, and the traffic organization evaluation model of plane interchange based on combined weighting-TOPSIS method is constructed. Taking the 3 traffic organization modes of the plane interchange of West Middle Ring Auxiliary Road and Xinghua West Street in Taiyuan for example, in continuous working days, traffic data are obtained through intersection volume investigation, point sample delay investigation, headway and speed investigation, the VISSIM intersection simulation model is established, and the evaluation indicators are obtained directly or indirectly. The advantages and disadvantages of various schemes are determined through the proposed combined weighting-TOPSIS method. The calculation result is consistent with the actual situation, which verified the rationality of the method. The result can provide theoretical support for the rational evaluation of the traffic organization of urban plane interchange or the regional traffic organization scheme using this idea.