Division Method Of Grid Network Control Sub-region Considering Macroscopic Fundamental Diagram

Adopting scientific coordinated control measures is an effective means to cope with regional urban congestion and improve the utilization of road network resources.On the one hand,the implementation of control measures should consider the overall operational efficiency of the road network,on the other hand,the urban road network is so large and complex that it is hard to firsthand research the entire road network.Therefore,with the goal of improving the overall operation efficiency of the road network and coordinating control,the urban road network is reasonably segmented into several control subregions,which is more conducive to improving the effectiveness of coordinating control measures and solving the urban regional congestion problem.This paper evaluates the macroscopic characteristics of the road network based on the Macroscopic Fundamental Diagram theory,analyzes the mechanism of the influence of the signal control conditions on the characteristics of the road network,proposes the intersection correlation model considering the signal control conditions,and improves the Newman fast division algorithm based on this,and proposes a reasonable and correct control subzone division method.Finally,an example analysis is conducted using the measured data of Changchun city to verify the superiority of this method.The main research works are as follows:(1)The basic characteristics of MFD are analyzed and a modeling scheme is proposed.The MFD is classified into three stages of representation based on the characteristic analysis of MFD,and the basic model of three parameters of MFD is deformed and calibrated to construct the MFD model between the two parameters of total number of vehicles in the road network and departure flow rate of the road network.Then the three-stage classification method of MFD using GMM clustering and the fitting method of MFD function for each stage of the road network using least squares method are proposed.The foundation for the MFD-based road network evaluation methods in Chapters 3 and 4 is laid.(2)Analyze the influence of signal control on the characteristics of MFD.Analyze the characteristics of road network MFD and construct an MFD-based road network evaluation index system.Then the experimental road network is built to analyze the proportion of signalcontrolled intersections and the influence mechanism of signal control period on the macroscopic performance of the road network,which provides a theoretical basis for the selection of signal control conditions to construct the correlation degree model and then classify the road network,and also provides a reference for the optimization of signal control in the control subzone after classification.(3)An improved road network control subzone division method is proposed.Based on the analysis of the influence of signal control on the performance of road network,a comprehensive correlation degree model of intersection considering the signal control conditions is constructed by integrating the dynamic and static influence factors of road network.Then the Newman fast algorithm is selected,the correlation degree value is used to assign edge weights to the network structure,and the calculation method of the modular degree is redefined to realize the improvement of the algorithm,and the control subzone delineation method based on the improved Newman fast algorithm is obtained.And the example analysis is carried out to confirm the influence of the signal control conditions on the road network and subzone delineation,and also to confirm that the improved subzone delineation algorithm is more effective and superior.(4)Evaluation of control subzone division effect by MFD.The evaluation method of the division results considering coordination control and MFD is proposed,based on the subzone division results before and after the improved algorithm for signal control optimization,the simulation experiment of the optimized road network is carried out by Vissim software,the MFD graph of the road network under each optimization scheme is drawn,and MFD is used to evaluate the overall operation efficiency of the road network,which proves that the sub area division method proposed in this paper can effectively enhance the benefits of coordinated control of sub areas,and improve the overall operation efficiency and carrying capacity of the road network.Therefore,the research in this paper provides new ideas for the division of urban road network control sub-areas,and has certain guiding significance for traffic control measures.