Research On The Improved Supernetwork Based Multi-modal Public Transport Assignment Model And Software Implementation

Under the guidance of the strategy of giving priority to the development of public transport,many large and medium-sized cities in China have formed a multi-modal public transport structure with the rail transport as the backbone and the conventional public transport as the main body,supplemented by other public transport modals.In view of the need to improve and perfect the transit assignment models and practical software modules applicable to the domestic multi-modal public transport network,this paper carried out "Research on the improved supernetwork based multi-modal public transport assignment model and software implementation" to provide the technical support for improving the service quality of the urban public transport system.Firstly,the features of multi-modal public transport were analyzed from two aspects,the model feature and network feature;using the hierarchical strategy,an improved multi-modal public transport super-network model based on hierarchical strategy was proposed,which consists of three layers,a key hub station layer,a hub station layer and a base station layer;based on the given judgment conditions for the effective path of the multi-modal public transport network,by comparing the existing effective path searching algorithms,it was decided to use the DFS algorithm,one of the graph traversal algorithms,to search the effective path of the multi-modal public transport network,and a method for generating the effective path sets of a multi-modal public transport network which meets the conditions for determining the effective path was proposed.Secondly,based on the improved public transport super-network model,the generalized cost calculation method of the path and the arc segments(including traveling arc,transfer arc and boarding and alighting arc)that constitute the network were studied;two types of congestion effects were studied,including the increase of station waiting time and the increase of passengers’ perception of travel time due to the increase of the arc flow;based on the improved public transport super-network model,three multi-modal public transport passenger flow assignment methods suitable for the practical engineering application were given,the capacity limitation-shortest path assignment,the capacity limitation-multi-path assignment and the stochastic user equilibrium assignment.Thirdly,the system design of the improved super-network based multi-modal public transport assignment module was carried out from the two aspects,module function design and database design;the above three practical multi-modal public transport passenger flow assignment methods were implemented using the Visual C++ programming language,including the capacity limitation-shortest path assignment,the capacity limitation-multi-path assignment and the stochastic user equilibrium assignment,thereby the transit assignment module of Tran Star software was improved and perfected;the method that how users use this module was briefly introduced.Finally,using the developed software module,an improved super-network formulation experiment,an effective path set generation experiment and a public transport passenger flow assignment experiment were carried out on the Nanjing multi-modal public transport network database;the results of the effective path set experiment showed that by using the hierarchical strategy to improve the super-network model,the total number of nodes and arcs can be effectively reduced,thereby reducing the size of the network and achieving the purpose of improving the efficiency of the effective path searching;the public transport passenger flow assignment experiment compared and analyzed the assignment results of the capacity limitation-shortest path assignment,the capacity limitation-multi-path assignment and the stochastic user equilibrium assignment,and the results showed that compared with the capacity limitation-shortest path assignment,the assignment results of the capacity limitation-multi-path assignment and the stochastic user equilibrium assignment were more evenly distributed on the network,which was more in line with the actual situation.