Analysis Of Complex Transportation Networks

Many complex systems in the reality can be depicted by networks composed by vertices and edges. The development of global economy and information technology has increased the scale of various networks and enhanced the complex interaction in the networks. Therefore the study of large scale complex systems has become the hot frontier research issue in the international research academy. Transportation networks as typical large scale complex systems are the important physical infrastructure for the social and economic development. It has become a urgent call from the academy and industry to systematically study the inner operation mechanisms in the transportation networks and complex interactions between the micro and macro levels so as to increase the design, plan and management level of transportation networks.This dissertation employs multiple research methods and technologies including management science, simulation technology, transportation user equilibrium model and complex networks theory. It is aimed to analyze the topological properties of large scale transportation networks, unveil the inner correlation between the micro and macro levels, and finally to provide new perspective and decision support for transportation management in the future.The organization of the dissertation follows the common rules of people getting to know new things: empirical research, modeling, theoretical analysis and practical applications. The dissertation systematically explores the complexity of transportation networks step by step. First we have done empirical studies of air transportation networks, urban street networks and maritime transportation networks and found that these networks have the same properties although they are different in the network type, function and scale. Second, we set up two evolution models based on passengers behavior and economic rules to explain how these topological properties come into being. Then we study the impact of topological properties on the passengers' behavior in the networks and propose an efficiency evaluation measure suitable for complex transportation networks. Finally we discuss the transportation service supply chain composed by those such as airline companies, airports, agents and use a multi-agent model to simulate the complex adaptivity in the transportation supply chain.This dissertation has mainly achieved the following work:1. We did empirical studies of air transportation networks, urban road networks and maritime transportation networks and proved that these networks have the same properties although they are different in the network type, function and scale. Their degree distributions all follow power-law distributions which is the characteristic of scale-free networks. There are some critical nodes playing important roles in the whole networks. Destroying these nodes can disable the function of the networks. Specially we show that the rich-club phenomenon in the airline and ship networks has direct relationship with the hub-and-spoke structure widely adopted in the transportation industry.2. Study the dynamic evolution process of transportation networks and propose two weighted networks evolution models. the first model is based on the passengers' transfer behavior in the airline networks. Based on simple rules, it gets theoretical solutions and simulation results conform with theoretical predictions. The second model is based on economic consideration. The scale of economic and congestion in the transportation networks is taken into consideration in the evolution mechanism. The simulation results gives truncated power-law distributions. The two models show that the transportation networks' properties in the macro level are related with the passengers route choice in the micro level.3. Study the efficiency evaluation problem of transportation networks. We propose an efficiency evaluation model for the transportation networks. And apply this efficiency evaluation measure in the empirical study of China airline networks and airports cluster in the Yangtze-River Delta. The result are expected to help the government decision.4. Study the relationship between the topological structure and user equi- librium status. Based on the classic traffic flow assignment model, we calculated the user equilibrium status of various network structures and found that average shortest path length and measure can5. Explore the transportation service supply chain networks and discuss the future research direction. Specially we study the complex adaptivity of the transportation service supply chain. Based on the multi-agent model we simulate the competitive and cooperative behavior of firms in the transportation supply chain. The result reveals that the "co-optive" strategy is more effective and more productive in establishing cooperative relationships than pure competitive and pure cooperative strategies, which reflects the present complex environment in the transportation industry.5. Start a preliminary study of transportation service supply chain networks and give a outlook. Specially for the complexity of competitive and cooperative firms. We adopt the multi-agent modeling.