雨天环境下高速公路交通流特性及模型研究

Traffic Flow Characteristics and Models of Freeway Under Rain Weather

降雨对高速公路交通流会产生一定的影响。为量化分析不同强度降雨对高速公路交通流微观和宏观特性的影响程度,根据实际观测的高速公路交通流和降雨量数据,确定了各种降雨类型下微观交通流特性参数(如速度、车头时距、车头间距等)的分布规律;对经典的宏观交通流模型进行了对比分析,选择Van Aerde模型作为雨天环境下高速公路交通流模型,运用启发式算法对各种类型降雨下的模型参数进行了标定,并给出了不同天气下交通流量-速度关系曲线和速度-密度关系曲线。结果表明,与无雨天气相比,小雨、中雨和大雨天气下高速公路平均速度分别下降4.7%、9.8%和16.1%,通行能力分别降低10.5%、17.4%和27.1%。

Rainfall has certain impact on freeway traffic flow. In order to analyze effects of rainfall on microscopic and macroscopic characters of traffic flow, actual freeway traffic and rainfali data were collected, and the microscopic charac- ters such as distribution of speed, time headway and space headway were determined. The Van Aerde model was selected to establish traffic flow model under rain weather, after comparing several classic traffic flow models. The parameters of Van Aerde model were calibrated Using heuristic algorithm based on actual data, and diagrams of volume-speed curve and speed-density curve under different rainfall were described. The results show that, comparing with dry weather, average velocity were decreased by 4. 7%, 9. 8% and 16. 1%, while traffic capacity were decreased by 10. 5%, 17. 4% and 27. 1%, under light rain, medium rain and heavy rain.