Complexity And Co-opetition Of Urban Bus Transport Networks

Bus transport has the characteristics of flexible route setting,wide coverage and good accessibility.It is an important transportation mode for urban residents and has occupied the dominant position in China's urban public transport systems.At present,bus transport has been formed a considerable scale of the network in major cities to almost achieve "full coverage".The dissertation takes bus transport as research object to analyze the complex structure of urban bus transport network from the macro level and discuss the competitive game and cooperation feasibility for the bus routes in the operation process from the micro level.The competition and cooperation relationship between bus routes is considered in the former.It can be a connecting point between the two.The research results are of great significance for deepening the basic theory of urban public transport system planning and operation.Urban bus transport networks are complex systems that consist of routes,stations,and passenger flow.The routes are divided into uplinks and downlinks.The concept of duplication factor is introduced to analyze the differences between uplinks and downlinks in Harbin.Directed-Space P representation model is proposed for bus transport networks and is applied to bus transport network of Harbin(BTN-H).Two important empirical characteristics are reported.The cumulative distributions of weighted degree,degree,the number of routes that connect to each station and peak-hour trips at each station uniformly follow the exponential distribution law.There is a rich-club phenomenon in BTN-H.Disassortative behaviour and the homogeneity of each station‘s connections are analyzed by the correlations and disparity.The passenger-crowding characteristics of BTN-H are analyzed from a route-based perspective and a network-based perspective.The suggestions of optimizing network service frequency are proposed for the routes and stations in the imbalance between supply and demand.Passenger-crowding was found to occur primarily in the middle of the routes,and the number of crowded sections decreased from the middle to the head and the tail.Many routes possess the characteristic of one-way passenger flow and two-way passenger flow in Harbin.The concepts of crowded degree and crowded length are introduced to evaluate crowd level of stations and travel paths.BTN-H in peak hours has reached a high crowd level.The statistical characteristics of path length,weighted degree,and edge weight are further analyzed.Specifically,detour coefficient is defined to quantitatively analyze the detour situation of the paths between bus stations in Harbin.The concepts of competitive coefficient and cooperative coefficient are introduced based on passenger travel OD distribution to measure the competition and cooperation relationships between bus routes.Competitive–cooperative space R representation model is proposed for bus transport networks.This model is applied to bus transport network of Shenyang(BTN-S)for analyzing competitive–cooperative situation and networked characteristics.The competition and cooperation is a kind of important relationship between bus routes,and cooperative relationship holds an absolutely dominant position.Competitive strength and cooperative strength are defined to analyze competition and cooperation between bus routes and their associated routes and to identify the hot routes and key connection routes.BTN-S based on competitive relationship has an obvious community structure using the modularity detection.An operating profit–optimization model is first formulated for a single bus route to illustrate the significance of competition between bus routes.Taking bus headway as decision variable,perfect-competition and imperfect-competition models are formulated for two bus routes to maximize every route‘s operating profit.The validity of the models is demonstrated based two numerical case studies and transferable analysis.The increasing laws of operating profit are founded for each route in competition with the changing headway.Operators can use game theory and decision theory to analyze their own departure strategy choices.The competition models proposed can be employed by public transport operators to generate optimal bus headways,and they also confirm theoretically that competitive game between bus routes is helpful in improving bus service efficiency.To break the traditional bus departure mode,the idea of cooperative operation among bus routes is proposed and the feasibility is discussed from the system point of view.Taking local bus transport network at a hub as an example,deficit function theory is used to describe the principle of cooperative operation among bus routes based on cross-line scheduling,including scheduling in a depot and scheduling between two depots.The result shows that cooperative operation among bus routes can reasonably allocate vehicle resources to maximally cut operating fleet size on the whole.It is conducive to reduce the operating costs of public transport enterprises.This dissertation aims at capturing some new characteristics in complexity of urban bus transport networks,involving passenger flow at stations and competitive and cooperative relationship beween bus routes;analyzing the state of passenger-crowding and the supply–demand situation of bus services from a network-based perspective;exploring the bus transport operation mechanism based on competition and cooperation.