Network Modelling And Optimization Design Of Urban Multimodal Transit System

The construction of a user-oriented and friendly transit system is considered as one of the efficient methods to alleviate the severe traffic congestion and to guarantee the sustainable development of a city.Driven by the national development strategy of public transport priority,the urban transit system in China has experienced a dramatic change over the past decade.A hierarchical urban multimodal transit system could be constructed on three levels: i)The rail system acts as the backbone of the multimodal transit network and provides rapid and longdistance services;ii)The main bus lines connect rail stations that have high passenger volume but are not directly connected by rail lines to provide mid-distance services;and iii)The ad hoc feeder lines serve as the supplementation for rail and main bus lines by delivering first/last mile services between rail stations and passengers' origins/destinations.Hence,it is of great significance to study the crucial problems in the multimodal transit network modelling,such as the investigation of the relationship between involved stakeholders,the optimization of available transit resources,in order to achieve the enhancement of operational efficiency of urban public transit.This work was sponsored by the Distinguished Young Scholar Project of the National Natural Science Foundation of China(71822007)and the Scientific Research Foundation of Graduate School of Southeast University(YBPY1835).This work tries to explore and analyze the optimization of multimodal transit network design by using the multi-source data fusion technique.Results provide theoretical basis for the planning and operation of urban transit system.This work is separated into the following contents:First,a multi-source data fusion method is proposed to explore the passenger's spatial and temporal distribution.The passenger's boarding stations are identified by the clustering method by using the IC card data and bus GPS data.Considering the limitation of the flat fare policy,the passenger's alighting stations are estimated by using the trip-chaining theory.The proposed methodology is illustrated in a field study with high accuracy.Second,to accommodate various aims of different planning horizons,the work proposed two models of the optimal design multimodal transit network for long-term and short-term planning,respectively.The long-term network design problem is formulated as a locationrouting problem,where the information of passenger demand distribution is incomplete.The short-term network design problem is constructed in a hub-and-spoke network framework,where a subset of rail transit stations is considered as hubs which is connected by a set of main bus lines.Third,the transit system planning and operation process is a game of three stakeholders:the urban transport authority,the bus company and travelers.The relationship between the urban transport authority and the bus company is described as a principal-agent game.The transport authority entrusts the bus company and subcontracts the operation of transit services to it.Considering the asymmetric information,an incentive mechanism based on the passenger's elastic demand is proposed to encourage the bus company to increase the system's level-ofservice.An optimization model is then proposed to obtain the optimal fare structure under flat fare,mileage-based fare and origin-destination-based fare policies.Finally,the demand-responsive customized bus is taken as the feeder for the multimodal transit system.a new optimization model for the network design problem of the demandresponsive customized bus.The proposed model consists of two phases: inserting passenger requests dynamically in an interactive manner(dynamic phase)and optimizing the service network statically based on the overall demand(static phase).In the dynamic phase,we propose a hierarchical decision-making model to describe the interactive manner between the operator and the passengers.The study provides beneficial theoretical support and reference for the multimodal transit network modelling and design in urban areas.