摘要
In order to improve the smoothness of traffic flow on bidirectional two-lane highways, an analytical method is proposed to optimize the minimum spacing of the signalized intersections. The minimum signal spacing is determined by two parts, including the necessary distance for stabilizing the traffic flow after it passes through the signalized intersections and the length of the upstream functional area of intersection. For the former, based on the platoon dispersion theory, the stable distance determination problem of traffic flow is studied and a model of dispersion degrees varying with the distance from the upstream intersection is presented, in which the time headway is intended to yield the shifted negative exponential distribution. The parameters of the model for medal and collector highways are estimated respectively based on the field data. Then, the section at which the slope of dispersion degree curve equals -0.1 is regarded as the beginning of the dispersion stable state. The length of the intersection upstream functional area is determined by three parts, including the distance traveled during perception-reaction time, the distance traveled while a driver decelerates to a stop, and the queue storage length. Based on the above procedures, the minimum signal spacing of each highway category is proposed.
为促进双车道公路交通流平稳运行,提出了信号交叉口最小间距优化分析方法.最小间距由交通流稳定距离和交叉口上游功能区长度2部分确定.首先,基于车队离散理论研究了交通流稳定距离的判定问题,构建了车速离散度函数随断面距离变化的模型,其中车头时距服从负指数分布;基于现场调查数据,分别针对干线型及集散型双车道公路标定模型,将离散度曲线取值-0.1处视为达到交通流离散稳定状态.对于交叉口上游功能区长度,可根据感知反应时间内行驶距离、减速距离及排队长度3部分确定.基于上述方法,确定了双车道公路信号交叉口最小间距.
基金
The National Natural Science Foundation of China(No.51208100
51308192)
