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充分发挥地面公交的优势是改善城市交通拥堵状况的关键之一。选取线路长度、线路网密度、重复系数、非直线系数、站点密度、平均站距、站点覆盖率等指标，应用地理信息系统（GIS）技术，对北京市地面公交线路网进行了现状评价。结果表明，尽管北京市的地面公交比较发达，近年来更是取得长足的发展，但仍存在线路长度总体偏大，线路网密度偏低，重复系数大且在空间分布上差异明显，80%以上线路的非直线系数超过《城市道路交通规划设计规范》标准，站点密度相对较小，站点覆盖率仍然不能够充分满足居民对公交的方便利用等问题。对现存问题的揭示将为提出合理的解决对策、进一步制定线路优化方案、提高地面公交的运行效率奠定基础。

Evaluation of the Public Bus Network in Beijing

Public bus plays an important role in resolving urban traffic congestions.The study has selected such indexes as: line length,network density,repetition coefficient,non-linear coefficient,stop density,average distance between stops and stop coverage for the evaluation of public bus in Beijing with the support of GIS technology.It has been found that there are still some problems in the bus network,although public bus in Beijing has been greatly developing,especially in recent years.The problems revealed in the study are that the length of the line is too long on the whole and the network density is low relatively.Both the repetition coefficient and its difference in spatial distribution are large,and the indexes of non-linear coefficient,stop density and stop coverage are not consistent with the standard values.The results can help to present reasonable countermeasures and optimized projects for improving public bus efficiency.