基于MFD的城市路网运行状态分析及关键路段辨识——以青岛市为例

Analysis of urban road network traffic status and identification of critical links based on macroscopic fundamental diagram:Taking Qingdao as an example

宏观基本图(MFD)是刻画路网平均流量和平均密度的关系模型,对路网运行状态分析、出行者路径选择和宏观交通控制有重要的作用。以青岛市台东商圈交通流检测器数据为基础,分析城市路网运行状态,并提出一种基于MFD的关键路段辨识的重要度指标,进一步识别路网中的关键路段。结果表明:青岛市台东商圈路网宏观基本图存在"磁滞现象",且在时间序列上呈现"M"状分布;据对其工作日、周末和节假日的宏观基本图分析,发现不同时段的路网运行状态存在差异;在关键路段的识别中,采用了MFD对比与重要度指标测算相结合的方法,验证了指标模型的合理性和准确性。

As a model describing the relationship between average flow and average density of road networks,the macroscopic fundamental diagram(MFD)plays an important role in traffic status evaluation,travelers’route choices and macro traffic control.In this paper,the traffic status of urban road networks was analyzed based on the data of traffic flow detector in Taidong commercial circle of Qingdao city,and an important index based on MFD was proposedto identify the critical links in road networks.The results show that there exists the phenomenon of hysteresis in MFD of Taidong commercial circle in Qingdao and its distribution takes on"M"shape in the time sequence.By analyzing the MFD of working days,weekends and holidays,it is also found that there is difference in the traffic status of road network during these three periods.In the identification of critical links,MED comparison and calculation of major indices were combined to verifythe rationality and accuracy of the index model.