Evaluation of Accessibility in Urban Rail Transit Network of Beijing Based on Transfer Efficiency Index and the Analyze of Its Cause
构建了换乘效率指数，对比北京、上海、广州的轨道交通网络，发现北京效率最低；通过分析北京1988年以来8个时期的网络演变，指出其重规模扩张、轻效率提升的问题，并讨论了外部线路过多、中心城区线路不足等缺陷及改进措施。
Based on improving of dispersion index,which is used to describe the accessibility of network system,transfer efficiency index is built in order to reflect the overall convenience of urban rail network structure in a way of transfer convenience.By comparing the efficiency of the rail networks between the cities of Beijing,Shanghai and Guangzhou,this paper has found that of the three,Beijing is the least efficient.This research was conducted by examining the evolution of the Beijing rail network over 8 periods of time beginning in 1988 and found that the current situation of the efficiency in Beijing rail network is caused by its emphasis on scale expansion and neglect on efficiency improving,and transfer efficiency in Beijing declined generally before 2011 and increasing growth over recent years.At the end of this paper,rail transit problems in Beijing are discussed,such as the high property of the external lines,lack of central city route network and unreasonable planning,and improvement measures proposed.