Research On Computer Model Construction Technology Of Urban Multi-Mode Public Transit Network

With the increase of cars in China,traffic congestion,environmental pollution,high incidence of accidents and other issues become increasingly prominent.However,“Transit Priority” policy,as to alleviate the problem of urban traffic has become a consensus.Professor Wang Wei has pointed out that if we want to work out urban congestion problem,we must establish the urban multi-mode transit system,which also depends on the analysis and evaluation of multi-mode transit network technology.TranStar is traffic analysis software developed independently and occupying a large share in China,which is in line with the traffic characteristics of China,but it lacks a systematic multi-mode transit network analysis module.Based on this,this paper studies the construction technology of urban multi-mode transit model.Multi-mode transit system is established.Based on the current development level of urban multi-mode transit system in China,this paper divides urban public transport into three modes: conventional public transport,bus rapid transit and rail transit.By studying the traffic characteristics and network structure characteristics of different transit modes,different transit sub-networks is established.In this paper,the transfer is divided into two kinds,including transfer inside the same station,and transfer behind different stations.Through transfer,different sub-network is connected to form the urban multi-mode transit super network.The computer expression method of multi-mode transit network is given,in order to describe the whole network and its properties.The contents include the route direction,station,and fare information of the conventional bus network,bus rapid transit network and rail transit network;and node,station and transfer information of the whole multi-mode transit network.The transfer expression method and related algorithms based on super network are also proposed.By designing a small multi-mode transit network,the method proposed is used for computer expression.A new generalized cost function based on value oftravel time,considering about time,ticket price and transfer effect is established.In view of the travel time of the bus section,this paper analyzes two scenarios including setting no transport capacity limit and setting transport capacity limit,and considers two cases of setting no bus lane and setting bus lane,and gives the model respectively and corresponding parameter calibration method.Based on the measured data of Wuxi City,the generalized cost function model of the city is given.An improved Dijkstra algorithm is proposed and the multi-mode transit assignment is carried out.According to the characteristics of multi-mode transit super network,the network storage structure and path searching algorithm are selected,and an improved Dijkstra algorithm is proposed to improve the operation efficiency.Based on the previous research results of transit passenger flow assignment,a capacity limit distribution algorithm of multi-mode transit network is proposed considering congestion effect.By sorting out the distribution results,the transfer coefficient and other parameters are put forward for the analysis and evaluation of the urban transit network.The passenger flow distribution program of urban multi-mode transit network is designed,including program module design,database design and interface design.Based on the road network of Wuxi City,according to the established multi-mode transit network and the calibrated generalized cost function model,the traffic assignment n of the multi-mode transit network in Wuxi city is carried out,and the distribution results are analyzed simply.