Research On Externality Mechanism And Evaluation System Of Urban Rail Transit

With the accelerating process of urbanization, the existing level of urban transport in China cannot meet the actual needs of urban development. High speeds, large volume, less pollution, more efficiency are advantages of urban rail transit, which can ease traffic congestion, save energy and reduce emission effectively. Furthermore, its enormous externalities play an important role in urban economic society. In China, the strategic position and construction level of urban rail transit have been improved in the past several years, and have a bright way to go in its future development. In order to exert urban rail transit's active effects, it makes sense in both theory and practice to analyze the mechanism of urban rail transit's activities and evaluate its impaction comprehensively.In this paper, the externalities of urban rail transit are divided into four parts such as transport functional effects, environmental effects, economic effects and social effects firstly based on the externality theories and product characteristics of urban rail transit. Secondly, describing the operation paths of those four external effects to reflect the mechanism. Thirdly, author establishes the externalities evaluation system of urban rail transit, introducing the principal component analysis method to calculate the comprehensive evaluation index. Finally, empirical studies carried out in Beijing as an example. Results show that the positive externalities of urban rail transit in Beijing are greater than the negative, and constantly emerging in an overall upward trend; the most obvious external effects contain the transport functional effects as well environmental effects; however, the economic effects and social effects increase moderately. The conclusions prove the reasonableness of mechanism analysis and the practicability of the evaluation model from the empirical point of view.