中文摘要：

为克服美国联邦公路局开发的函数（BPR函数）的一些内在缺陷,在保留BPR函数的优良性质的基础上,提出一个能弥补其不足的改进路阻函数.该函数具有BPR函数的一些性质和更短的计算机运行时间.采用两个实际项目进行交通影响分析并运用EMME软件配流检验该函数的性质,结果表明该方法有效.多数情况下,BPR函数中的参数可以直接移植到改进的路阻函数中去.

英文摘要：

To overcome some inherent flaws of the function （ BPR function） developed by the US Federal Highway Administration, on the premise of retaining the excellent properties of BPR function, an im- proved impedance function that can make up for its shortcomings is proposed. The function has some properties of BPR function and shorter computer running time. Through traffic impact analysis on two ac- tual projects and using EMME software to assign flow, the properties of the function are tested. The re- sults verifies the effectiveness of the method. In most cases, the parameters of BPR function can be di- rectly transplanted into the improved impedance function.