快速路菱形立交出入口间距设置及适应性研究

应用Vissim仿真模型研究了在不同的主辅路流量组合和交织流量比下,菱形立交出入口区间平均速度、平均最大排队长度、出口流量与出入口间距的关系.研究表明,交织区平均速度、平均最大排队长度和出口流量都随出入口间距的变化而变化.当主辅路流量和交织流量比较小时,三者随出入口间距变化较小；当主辅路流量和交织流量比较大时,三者随出入口间距变化较大.因此可以得出,当交通流量较小或出入口间距受限时,出入口间距为l00 m时比较适宜；当交通流量较大时,随交织流量比由0.2增大到0.3以上时,出入口间距应由300 m增大到450m,才能有较好的运行状态.

Spacing Establishment and Adaptability of the Exit and Entrance of Urban Expressway Diamond Interchange

Using the Vissim simulation model,the paper studies the relationship between the average speed,the average maximum queue length,the exit flow and exit-entrance spacing of diamond interchange in the case of different traffic flow combinations of main and side roads and volume ratios.It shows that the average speed of weaving area,the average maximum queue length and the exit flow change with the exit-entrance spacing.When the flow of main and relief roads and volume ratios are small,the three change small.However,when they are big,the three also change big.Therefore,it can be known that the reasonable exit-entrance spacing is 100m when the traffic flow is small or the spacing is limited,and that the reasonable spacing should increase from 300m to 450m as volume ratio increases from 0.2 to 0.3 and above to realize stable operation when traffic flow is big.