Research On Urban Road Network Evolution And Transit Network Design Based On Heuristic Method

With the rapid advancement of China’s urbanization process and the rapid increase in the number of motor vehicles,most cities in China now face problems such as traffic congestion,environmental pollution and noise pollution.Faced with these problems,on the one hand,a road network with reasonable structure,proper layout and sufficient capacity has become an important basic condition for the sustainable development of urban transportation system.On the other hand,the development of public transport based on road network is the most effective way to solve urban traffic problems,however,the most basic step in the development of public transport is the design of public transport network.The research object of this paper is based on the above two starting points,namely,the evolution characteristics of urban road network topology,modeling and bus network design.In the first part,based on the complex network and graph theory,this paper studies the evolution characteristics of urban road network topology and related problems of model construction.Firstly,the urban road network topological structure is abstracted as a network by the original method,and the urban road network is quantified by using the method of geometric and complex characteristics of the urban road network.Secondly,the elements of urban road network evolution system are analyzed.Based on the evolution elements and process of urban road network,two important effects of the evolution of urban road network topology are proposed: self-organized effect and planning effect.Finally,based on the existing model research results and the inspiration of RNG proximity graph generation method,this paper quantitatively proves that the growth of urban road network is controlled by two basic continuous processes: expansion and densification.In order to reproduce these two processes,we propose a model to generate nodes and road sections by considering relative neighbor preferences and angle constraints.The parameters,such as node degree distribution,betweenness centrality,network cell structure,network efficiency and shape factor are simulated.The statistical properties of the macro and micro indicators of the model are in good agreement with the observed empirical models.In addition,the model successfully reproduces the tremendous diversity of road network models.The similarity between the characteristics of the model and the empirical results shows that there is indeed a mixed mechanism of self-organized behavior and planning behavior in the spatial growth of urban road network.Based on the model and its extension,it can be used to evaluate the structural characteristics and driving efficiency of the road network,predict road network expansion and guide urban road planning and modification.The second part is based on the bus network design of the bee colony algorithm.A public transit network design model based on Bee Colony Algorithm is proposed.The model takes the variance between the total passenger travel time and the network traffic as the total cost to construct the objective function,and takes the minimum and maximum number of transit stops as the constraints.In order to balance the traffic of the whole public transit network,the traditional Greedy Algorithm is improved to generate the initial solution,and the initial solution set is improved by cyclic iteration until the required bus network is generated.Finally,the Swiss Mandl standard network and the road network generated by the first part of the model were verified,proved the validity of the model.