城市快速路出入口交织流率和交织长度的仿真研究

Simulation for the Weaving Ratios and Lengths of Weaving Sections of Exits and Entrances of Urban Expressways

城市快速路出入口是引发相关路段及其周围路网拥堵的主要原因。交织流率和交织长度是影响出入口处交通运行的重要因素,并采用仿真方法对两者进行了分析,具体案例的Vissim仿真结果表明:通过总流量为4 900veh/h,流率比由0.15增加到0.4时,交织段均车延误增加2倍,交织车速降低将近40%;交织长度选取160～180m时,均车延误为1.3s,平均车速达到45.02km/h,是快速路出入口交织长度的合理值。

The accesses（entrances or exits） of urban expressways are the primary causes for the congestion on related road sections and peripheral roadways.It is found out that the following two factors are important in this regard： the weaving ratio and the length of weaving section.The results from the specific simulation studies through Vissim show that,when the total flow is 4900 veh/h and the weaving ratio increases from 0.15 to 0.4,average delay per vehicle is doubled over the weaving sections,while the interweaving vehicle speed reduces nearly 40%;when the lengths of the weaving sections are selected in the range of 160～180m,every vehicle delay is only 1.3s and the average vehicle speed is about 45km/h.These values are found to be the reasonable values for designing the length of the weaving sections at the exits and entrances of urban expressways.