Coordinated Rail Transit Network Design Theory And Methodology Under A Regional Multilevel Network

In recently years,the urbanization process in China has gradually shifted from the integrated development of urban and rural areas in a single city to regional coordinated development based on city clusters and metropolitan areas.In these vigorous and prosperous areas,multilevel and multimodal rail transit(like subway,high-speed railway,suburban railway)has been rapidly developed.Masses of rail transit infrastructures are planned and constructed to accelerate the formation of a more accessible rail transit network,and different rail transit modes are going to be coordinated.The rail transit network becomes a basic support for regional integration.However,rail lines of different service areas and different administrative departments are mostly considered from its own single network at the planning stage,which causes some shortcomings like inconvenient transfer and insufficient connectivity.And these shortcomings directly deteriorate the transport efficiency and service quality of the public transportation.Therefore,it’s necessary to propose a regional rail transit integrated planning theory and methodology from the perspective of a comprehensive network comprised by multilevel and multimodal rail transit lines.In this context,the dissertation reviews relevant theories and methodologies in the literature,and analyzes the inadequacy and main problems of rail transit system in China with the comparison of domestic and foreign rail transit current situation.The research firstly studies the travel demand at different spatial scales from regional perspective.Taking the travel demand as the input,coordinated rail transit network design model and algorithm in the metropolitan area are proposed under a multilevel network,and furtherly coordinated rail transit network design model and algorithm of intercity railways are proposed under a scale of city cluster.The research can help to integrate multilevel and multimodal rail lines in a region from the horizon of planning,and can lay the foundation for improving the transport efficiency of the rail transit system and shortening total travel time for travelers in the operation phase.The main research contents of the dissertation are as follows:(1)Research on travel demand analysis theory and methodoloy for regional rail transit network design under a multilevel network.Open-source data and open-source tools are utilized to obtain demand nodes(bulit environment like buildings and other land use)and multimodal transportation networks in the area of interest.The advantage is to break the limitation of administrative division and different transporation modes,even agencies.By learning the metropolis model of Chicago and Pittsburgh,the dissertation introduces proportional hazard model to forecast travel demand distribution based on the classical fourstep model.The trip distribution between traffic analysis zones is obtained under the influence of built environment(like transportation network and land value).The travel demand and the transportation infrastructure are the inputs to the following network design models in the dissertation or the basis of other related researches.The proposed method enriches and expands the theoretical research and engineering practice of traffic demand forecasting.(2)Research on coordinated rail transit network design theory and methodology under a metropolitan multilevel network.Long-distance intercity lines may interfere the optimization of other lines in the metropolitan area.Separated from intercity lines,the dissertation studies the network design method of urban rail transit lines,suburban rail transit lines or transfer hubs for intercity railways in a metropolitan area.Based on the hierarchical coordination theory and the situation of regional development,candidate new links can be put forward.Considering the selection of travel path from the travelers’ side,construction cost and investment,train’s operating cost,and other factors like link capacity and train capacity,the mathematical model is formulated to connect the dimensions of rail transit infrastructure,transport service supply,and travel demand.The objective is to minimize the system’s total generalized cost from the three sides of investment,operation and travel.A column generationbased algorithm is designed to obtain construction plan with high quality,and to determine the travel path for each traveler,transport supply on each link simultaneously.The case studies with multiple scenarios reveal that irrationally adding new lines to the rail transit network may trigger Braess’ s Paradox.The corresponding representation in rail transit network is proved and analyzed.Meanwhile,the validity and practicability of the proposed coordinated network design model and algorithm are verified.(3)Research on coordinated rail transit network design theory and methodology of intercity railways under a multilevel network at the scale of city cluster.Based on the coordinated rail transit network design model and the optimization results in a metropolitan area,the network design problem of high-speed railways,conventional railways,and intercity railways in a city cluster area is studied.Since an intercity journey always involves different rail transit modes with different operating hours,space-time network with time window is introduced.The time windows of different rail transit systems’ service hours and travelers’ expected time windows for traveling are considered simultaneously in the model.Transport service supplies are expressed as a quantity of space-time arcs in the space-time network for operating trains.Then feasible travel paths in the space-time network are generated by timedependent forward dynamic programming algorithm to satisfy the travel demand and preference for individual travelers.In the mathematical model,travel demand and transport supply are matched by train capacity constraints.Finally,the model is solved to optimality and obtain the best construction plan of intercity railways as well as travel paths for each kind of travelers.The result analysis of case studies reflects the practical significance of coordinated rail transit network design of intercity railways under a multilevel network and shows the innovation of the proposed model.