城市快速路交织区通行能力估计模型

Capacity Estimation Model on Weaving Segments of Urban Expressway

为探究城市快速路交织区通行能力的特征及影响因素,选取上海市快速路60处典型交织区,利用其1年的交通流检测数据,首先根据交通流量-速度曲线确定20个可获取实际通行能力的交织区瓶颈点,然后利用统计分析计算各交织区通行能力,并分析典型因素对通行能力的影响,进一步提出适合城市快速路交织区运行特征的新通行能力估计模型,并与HCM2010中交织区通行能力回归模型和理论模型进行对比分析。结果表明:提出的模型对通行能力估计误差(3.6%),优于HCM2010模型(10.4%)和理论模型(25%);交织流量比、汇出流量比与通行能力之间存在对数函数关系,而交织长度、车道数则与通行能力存在线性关系;提出的模型适用性较好,尤其在交织流量较大的交织区,能更符合城市快速路交织区运行特征。

In order to investigate the characteristics and influencing factors of capacity on the weaving segments of urban expressway,based on traffic flow detector data in one year,20 available weaving sites were selected from 60 typical weaving segments on the expressways in Shanghai according to the flow-speed curves.Then the capacities of weaving segments were calculated through statistical analysis,and the impacts of the typical factors on capacity were analyzed as well.Finally,new estimation model which is suitable for the characteristics of urban expressway weaving segments was proposed. Three different capacity estimation models（HCM2010regression model,theoretical model and the new model）were also compared and analyzed.The results show that the estimation error of the new model（3.6%）,is smaller than that of HCM2010 model（10.4%）and the theoretical model（25%）.The logarithmic function relationship exists between the weaving volume ratio（RV）,diverging volume ratio and capacity,while the linear relationship between the weaving length,lane number and capacity.The new model has better applicability,especially for the situation when the value of RV is relatively high which is also more consistent with the operation characteristics of weaving segments on urban expressway.