Transfer Behavior Analysis And Shuttle System Coordination Of Railway Passenger Hub

With the rapid growth of high speed railway in China,modern railway stations,such as Beijing South railway station,Wuhan railway station and Chengdu East railway station,have been planned and constructed one after another,and moved on to the phase of operation and management.Being the important connectors of railway networks and urban traffic networks,these railway stations usually integrate variety of urban traffic modes including buses,subways,taxis,private cars as well as car-hailings.These integrated urban traffic modes along with the railway stations constitute the railway passenger comprehensive hubs.In one hub,the integrated multi-mode traffics provide transport services to and from the railway station for departure and arrival railway passengers between the station and their origins/destinations.Coordination performance of the shuttle system not only affects travel efficiencies of the railway passengers,but also affects functions of the railway comprehensive hub,benefits of the transportation providers as well as images of the city.The coordination of the shuttle system at the level of operation plannig mainly targets two subjects.The first one aims to coordinate the intermodal capacity assignment of each traffic modes.The second one aims to coordinate the transfer time within each traffic mode to optimize the departure frequencies.However,current studies suffer from the following shortages.First,current studies chose stated preference design strategies,which is the combination of experimental scenario numbers and design methods,in an arbitrary way.Further explorations are needed to provide better guidings to the constructions of SP senarios.Second,literatures on transfer behavior models can only describe the heterogeneities of preferences that passengers have on attributes but failed to express the heterogeneities of attribute process amongst passengers.Third,most researches fail to consider demand elasticities and its heterogeneities in the modeling of coordination,and have dealt with coordination of capacity and coordination of time as two separate problems.This kind of treatment neglected the relevance between capacity and time coordination under the perspective of elastic demand.Thus,to get better understandings of railway passengers'transfer behaviors and to realize simultaneous coordination of capacity and time in the shuttle system,this paper dealt with the following problems:Strategy choice of stated preference design,hybrid heterogeneity mode choice model construction for transfer behavior analysis,the value of transfer waiting time,the model constructions for the coordination of the shuttle system under heterogeneous elastic demand perspective of view.The accomplished works and conclusions are as follows.1.The components of the shuttle system are analyzed and the relationships among main subjects of the shuttle system are discussed,then the interactions among the policy,service and mode choice behaviors in the shuttle system are revealed and the necessity of considering passengers'transfer behavior in the study of shuttle system coordination is proved.The role of service level serves as the bridge between capacity coordination and time coordination is proposed,which indicates the feasibility of simultaneous coordination of capacity and time in the shuttle system.Two management mechanisms namely centralized directed mechanism and self-organized mechanism were proposed.The supply-demand equilibriums and the evolutionary paths on coordination of the shuttle system under the above mentioned two mechanisms are analyzed.These discussions can help to clarify the research strategies that are about to take in the following chapters including the quantitative descriptions on the heterogeneous elastic demands of mode choice behavior as well as the modeling for simultaneous coordination of capacity and time in the shuttle system.2.To improve the quality of survey data,this paper compared the statistical characteristics that stated preference experimental design methods have under different number of choice scenarios with the method of numerical analysis.Then a two-step experimental design strategy which combines the uniform design and efficient design method is proposed.Empirical studies are made with the mode choice problems in the access and egress shuttle system of Chengdu East railway station to test the proposed strategies.Results in both access and egress directions indicate that the proposed strategy inherits the superiorities of both uniform design and efficient design.It shows not only great flexibilities on scenario number choices,but also good performances on the goodness of fit of parameter estimation.It enables to improve survey efficiencies by decreasing the numbers of scenarios in experimental designs and by reducing the work load of distributions and recoveries of the questionnaires.Besides,attribute process heterogeneities including attribute none attendance and aggregation of common metric attributes are reported in the pre-survey rounds of both connected directions.Thus a self-reported investigations on attribute process are supplemented in the formal survey rounds of both connected directions to collect related data.3.Given the attribute process heterogeneities discovered in the survey,a hybrid heterogeneity model for passengers'transfer behaviors is proposed.Indicator variables for attribute none attendance are introduces and aggregation weights for aggregation of common metric attributes are added to accommodate the attribute process heterogeneities,while preference heterogeneities are expressed with discrete distribution assumptions.By doing so,the full attribute attendance assumption in traditional discrete choice model is expanded and the defects of mono preference expression is fixed,so that the explanatory abilities as well as expression levels of the hybrid model is improved.The BHHH algorithm is proposed to solve the maximum likelihood estimation problem on account of the complexity of finding analytical solution to the Hessian matrix of the log likelihood function of the hybrid heterogeneity model.Hybrid heterogeneity models and corresponding mono heterogeneity models are formulated for the shuttle system of Chengdu East railway station,then different model structures are tested are compared with the criteria of adjusted R~2,the normalized AIC index,the time expense in parameter estimation and the ability of capturing significant variables.Comparison outcomes indicate that the hybrid heterogeneity models have better performances on the goodness of fit and capability of model expressions than that of the mono heterogeneity models'in both access and egress directions.4.Modelling and discussions on simultaneous coordination of capacity and time are implemented under centralized directed mechanism and self-organized mechanism.Heterogeneous elastic demands are considered in the modelling with the form of estimated hybrid models.By doing so,the assumption of homogeneity elastic demands in traditional coordination optimization models is expanded and the defect of disperse coodination of capacity and time is fixed.An algorithm based on the NSGAII is proposed and the method for selecting the best comprised solution is presented in the centralized directed mechanism,on account of the characteristics of Pareto front in multi-objective optimization.A generalized Nash equilibrium model is formulated and the existence of its solution is proved under the self-organized mechanism.The solution is found with genetic algorithm by transferring the problem into a none-linear programming with none linear constraints.Case studies are implemented with the peak,the flat and the night hour of one day in the shuttle system of Chengdu East railway station.The effectiveness of proposed models are verified,the results under the two mechanisms are compared,and policy recommendations are proposed.This paper has not only improved the method for design strategy selection in stated preference survey,but also enriched the description ability of hybrid heterogeneity and improved precision of discrete choice models.Furthermore,it realized the simultaneous coordination of capacity and time under heterogeneous elastic demands considerations.Thus,it can provide methodology references and decision supports for the scheme formulation of shuttle system coordination at the level of operation plannig.