Urban Traffic Mode Structure Optimization Based On Eco-transportation

Urban eco-transportation system is the development direction of urban transportation in future, and urban traffic mode structure is an all-important factor that affects the realization of urban eco-transportation system. This paper takes eco-transportation as the basis, chooses traffic mode structure as the starting point; makes a research of the optimization of urban traffic mode structure which based on eco-transportation.This paper consists of five parts. The first part introduces the basic theory such as the meaning, the development objections and the influence factors of eco-transportation system, this could lay a solid foundation for the choice of optimization objections and constrains in the traffic mode structure optimization model. The second part makes a systemic explanation of traffic mode structure, it analyzes the characteristics of different traffic modes, the influence factors of traffic mode structure and its influence to eco-transportation and so on, and takes this as the basis to determine upper-lower bound of each traffic mode as well as a series of parameters. The third part analyzes the whole capacity of eco-transportation system, first expatiates the definition, then from space-time, eco-environment and energy resource three aspects to consider the whole capacity, as well as their calculate models, these make for the analyses of the supply-demand of urban transportation, so offer technical support for determining the traffic mode structure which conductive to the development of eco-transportation. The fourth part constructs the model. Firstly, according to the reasonable orientation of each traffic mode determine the development and the restrictive modes, and combine with citizen income, time value, superiority and characteristic of each traffic mode and so on to determine the upper-lower bound of each traffic mode. Secondly, analyzes the main objectives and constrains based on eco-transportation development goals, then establishes an fuzzy programming model as well as its derivation process of optimization of traffic mode structure based on uncertainty planning theory (consider the total traffic demand, the total road resource, the total energy resource and the total environments pollution have uncertainty in future, so these variables are expressed using fuzzy numbers). Additional, we use genetic algorithm to solve the model, and after the optimization, we could get a traffic mode structure, then take traffic assignment and traffic evaluation in order to identify the result whether or not satisfy the require of eco-transportation system. If not, take a next optimization until achieve the development goals of eco-transportation, so it is a dynamic optimization process. And it chooses ChangSha as example to analyze.