Optimization Strategies Of Urban Road Network Structure Based On The Route Choice Strategies Of Travellers

With the rapid economic development and the speeding urbanization in our country, the improvement of the traffic demand and intensity expands the scale of the urban traffic networks and increases traffic congestions continuously. In this case, how to ensure the normal and efficient transportation becomes more and more urgent. As we all known, the urban traffic systems are typical complex networks, so in order to solve the traffic congestion problem, we have to adopt the methodology of the scientific system theory to investigate the route choice behavior of all travelers in all networks and the optimal strategies of network structures. Therefore, in this thesis, the urban road network structure and the invulnerability are discussed firstly. Secondly, the route choice behaviors of all travelers are analyzed based on the route choice strategy. And then the node importance of the urban road network with dual approach and primal approach respectively. After that, the improvement strategy of the node capacity in the urban road network with dual approach and the edge addition strategy of the urban road network of the primal approach are proposed respectively. The details are as follows:Firstly, the analysis of urban road network structure and invulnerability. Take the urban road network of Deyang city for instance. On the basis of modeling the urban road network structure of Deyang city of the primal approach and the dual approach respectively, the structure features of the two models are studied by calculating the characteristic index of the network. Then the subgraph number, the scale of the biggest connected subgraph and the network efficiency are used to measure the network invulnerability. At last, the networks with primal approach and dual approach are attacked by the usual random and deliberate attacks, from which the network invulnerability is investigated.Secondly, the route choice behaviors are studied based on the route choice strategy. The average travel efficiency of all travelers of all OD pairs is studied on the basis of the route choice strategy, which is proper for the urban road networks. Given the average travel efficiency affected by the route choice and the node flow fluctuations, in this thesis, the real-time node flow is defined. Then take the urban road network of Deyang city of the dual approach for instance, the relationship between the route choice behavior weights, the node flow fluctuation parameters and the average travel efficiency are investigated by analyzing the changes of the minimal average travel efficiency curves.Thirdly, for the urban road network of the dual approach, the improvement strategies of the node capacity are proposed and the performances of the strategies are discussed. For the urban road network of the dual approach, the node importance of the urban road network is determined by the multi-attribute node importance evaluation method based on the information entropy. In this node importance evaluation method, the multi-attribute indices include both the static structural and dynamic indices. After that, the improvement strategy of node capacity based on the node importance is presented, and three other improvement strategies are proposed simultaneously to be compared with the improvement strategy of node capacity based on the node importance. In the end, the urban road network of Deyang city with dual approach is taken for example to do simulations. And the validity and the correctness of the strategies are verified by analyzing the changes of the average efficiency, the return and the performances under cascading failures among all improvement strategies.Fourthly, for the urban road network with the primal approach, the edge addition strategy based on the node importance is proposed, and the performances of the strategy are studied. For the urban road network of the primal approach, the node importance is sorted according to its importance by the multi-attribute node importance evaluation method based on the information entropy. Then the edge addition strategy is proposed, in order to verify the validity and the correctness of the proposed edge addition strategy, the random edge addition strategy is presented simultaneously, and the urban road network of Deyang city with dual approach is taken for example to do simulations. By comparing of the minimum curve changes of the average travel efficiency with the node flow fluctuations, the validity and the correctness of the strategy is verified by means of relationship between the number of increased edges and the average travel efficiency, and the characteristics changes of network structure after edge additions.In sum, in this thesis, the route choice behaviors of travelers on the urban road networks are analyzed first, and then the combination of the results of the route choice behaviors with the network structure features are used to calculate the node importance of nodes in the urban road network of the dual grapg and the primal graph. On the basis of the above, the improvement strategy of node capacity in dual graph and the edge addition strategy in the primal graph are proposed. At last, the urban road networks of Deyang city of the dual approach and the primal approach are taken for instance to do simulations respectively, and the average travel efficiency after the network structure improvement is analyzed. The analyses of the above provide scientific basis and means for the planning and construction of the topology of the urban traffic network.