中文摘要：

基于单一交通网的传统等时线算法具有较大的误差,为此本文提出了一种新的考虑步行网络的等时线算法.该算法的核心是构建交通网与虚拟步行格网相结合的通行网络,利用空间插值和空间分析原理生成基于栅格的时间成本分布图,并提取等时线.实验表明：本文提出的算法较传统等时线方法精度高.

英文摘要：

The existing isochrone algorithm solely depends on the transportation network which produces large errors. This paper presented an new isochrone algorithm by taking pedestrian network into consideration. Based on the combination of transportation network and pedestrian network, this algorithm created the isochrone with the spatial interpolation and spatial analysis theory. The experimental results showed that the isochrone algorithm would have a higher precision than the conventional method.