基于Edie模型的路阻函数关系推导及其拟合分析研究

A Deduction of Impedance Function Based on Edie Model and Its Fitting Analysis

路阻函数是交通分配中的关键因素。BPR函数作为一个广泛应用的经典模型,由美国公路局提供的推荐参数不能完全符合实际,在分配中并不能与现实情况密切吻合。基于Edie交通流模型,对拥挤和非拥挤情况下路段流量与走行时间之间的关系进行了推导,给出了一个路阻函数相关的表达式。通过与BPR函数的对比,分析了各自的优缺点,在继承BPR函数优点的基础上应用曲线拟合方法得出了一个可以替代BPR函数的关系式。

Link of Impedance Function is a key factor in traffic assignment, and BPR function is a classic model used widely, but the result in assignment does not always coincide with the actual situation, for its default parameter alpha and beta recommended by U. S. Bureau of Public Roads sometimes are not fit for the situation.The paper deducts the relationship between link flow and travel time in congested and non-congested condition based on the Edie Model, and gives an equation to express it. Comparing the equation with BPR function, some advantages and disadvantages a：re illustrated. In order to find a proper function to replace the BPR function, an exponent parabolic regression equation is illuminated by regression method.