基于最短路径的等时缓冲区分析及其应用

摘要

为了研究城市交通网络不同时段、不同交通方式居民出行的时间结构,从等时缓冲区数学模型出发,引入最短路径思想,得到网络节点间的最短时间距离,并以此作为缓冲区分析的量算指标和样本点数据.借助ArcGIS空间插值和等时线提取工具,实现交通网络时间距离表面和等时缓冲区(等时线)的建立及其可视化.通过具体的实例,生成闲时、忙时,小汽车、公交车出行的等时缓冲区数据,并进行统计、对比、叠加分析,阐述了等时缓冲区的基本特征,评价了交通网络的运行状况,为居民出行提供参考、为城市交通规划提供依据.%In order to study the time structure of the resident trips in different periods and the transport modes, the shortest time paths between network nodes were obtained with the mathematic model of isochronal buffer and traffic network theory. The shortest time paths can be used as a kind of quantitified index and the samples of buffer analysis.Using the spatial interpolation algorithm and analysis tools provided by ArcGIS software,the time distance and isochronal buffer (time contour) were established and visualized.The isochronal buffer's data has been acquired from a case which was under the consideration of two different periods (busy and idle) and transport mode (auto and transit). The basic characteristics of isochronal buffer were expatiated, and the operational state of urban traffic network was evaluated, which could contribute a lot to the decision-making for traffic planning as well as resident trips.