摘要
BPR函数计算路段阻抗时,没有反映出交通状况由畅通到拥挤的过程中交通量先增后减的事实,这与实际交通情况不相符,因此对BPR函数进行了改进:一种改进方法是随着拥挤程度的增加,将交通减小量与路段通行能力相加的结果作为交通量用于BPR函数,使得到的路阻值能够反映实际路况;另一种改进方法是用交通量和密度的关系式替换BPR函数的交通量,并根据前一种改进方法的思想对新得到的函数进行再改进,获得一个单调递增函数,这样可以不受路段通行能力限制,从而反映交通路况所对应的路阻.
The calculation result of link performance by BPR function is not in consist with practice, it is because BPR does not take into account the fact that traffic quantity increases to link capacity and decrease when traffic condition changed from free to congest. So in this paper some changes were done to BPR function in order to fit practice link condition. One way was adding traffic decrease quantity to link capacity for BPR function when congest happened, which could make link performance reflect practice link condition. The other way was replacing traffic quantity in BPR function with traffic density by equation, and it did some changes to the new function according to the idea got from previous way, then got a function which monotony increase by degrees, and it was not limited by link capacity and reflected practice link condition.
出处
《武汉理工大学学报（交通科学与工程版）》
2009年第3期446-449,共4页
Journal of Wuhan University of Technology（Transportation Science & Engineering）
基金
国家自然科学基金重点项目(批准号:70431003)
国家科技支撑计划项目(批准号:2006BAH02A09)
交通部科技项目(批准号:200439800060)
河北省科学技术研究与发展指导计划项目(批准号:072135214)资助
关键词
路阻函数
BPR函数
拥挤
交通密度
交通量
link performance function
BPR function
congest
traffic density
traffic quantity
