The Study Of Urban Rapid Transit Network Scale

With the development of economy and the urbanization process accelerates quickly, The number of cars increased to a range has brought tremendous pressure to traffic management, as well as the environment, which caused the problems of accumulation and transportation that affected the urban development. Urban rapid transit which has special technical advantages such as quickly, timely, safety, environmentally become the important strategic act to optimize transportation structure and ease traffic congestions for domestic and international metropolises. However, urban rapid transit is a systematic engineering with broad effect, deep comprehension and huge invest; the pre-planning of urban transit projects should be given highly admiration, especially the network scale which is a macro control variable.The development of urban rail transit network scale is subject to economic capital, urban land, traffic demand and other factors. The reasonable network scale is not only promote economic growth, but also affect the structure and functional localization of city immediately, which also has the function of guidance and feedback to urban land using. So it is very important to give research on the network scale.Based on the qualitative and quantitative analysis of domestic and international relevant research literature, this paper creates a new model to calculate urban rapid transit network scale using System Dynamics, considering the interaction between urban development and network scale, as well as the relationship between the internal traffic structure.Firstly, this paper illustrates the intensions and growth mechanism of urban rail transit network scale. Meanwhile, summarizes the relationship between the main impact factors of network scale factors by Interpretative Structural Model. Furthermore, the system dynamics models of urban rail transit network scale based on the flow chart of the network scale system. The model calibration and quantitative simulation are conducted to predict the future of Dalian urban rail transit network scale development process at different stages by vensim_PLE. In the model, different network scale growth schedule can be simulated by changing the policy variables, thus the relevant recommendations of network scale growth are advised.