低密度区高速公路平直段交通流速度和流量关系研究

Research of Speed-volume Relationship of Expressway Straight Section in Low-density Area

为确定高速公路基本路段低密度区速度和流量模型形式和模型参数是否与高速公路类型有关,研究了平原区开阳高速、山岭重丘区京珠北高速和山岭微丘区粤赣高速三条代表性的不同类型高速公路的平直段上的交通流。用摄像机在合适调查断面录制了足量视频作原始资料;权衡多方面因素后采用了20 s作为提取数据的统计间隔;利用方差分析判断出了同一高速公路不同车道上车辆速度均值有显著差异,速度和流量模型应分车道建立;将20 s流量折算成标准小汽车流量后放大为小时流率,速度采用20 s内通过断面的所有小型车平均速度,作速度和流率散点图;根据散点图建立了速度和流量模型。结果表明:低密度区不同高速公路平直段速度和流量关系虽均可用线性模型表征,但模型参数不同,而且同一高速公路不同车道的速度和流量模型参数也不同。

To determine the speed-volume model form of basic sections of expressway in low-density area and whether model parameters are related to expressway types, the traffic flows on straight sections of 3 typical types of expressway, i. e. , Kaiping - Yangjiang expressway in plain area, Beijing - Zhuhai north expressway in mountainous area, and Guangdong- ]iangxi expressway in mountainous hilly area are researched. Sufficient videos are recorded with camera in suitable survey sections as original data. After considering different factors, 20 s is determined to be the statistics interval for data extraction. The significant difference of mean vehicle speeds on different lanes of the same expressway is judged by variance analysis, hence, the speed-volume models should be established separately for different lanes. The traffic volume per 20 s is converted to standard car volume and enlarged to flow rate per hour. The scattergram of speed vs. flow rate is drawn based on the average speeds of all Small cars through survey section in 20 s. Based on this, the traffic speed-volume model is established. The result indicates that （1） although speed-volume relation of expressway straigbt section in low-density area can be expressed by linear model, the models of different expressways have different parameters, and the models of different lanes of the same expressway also have different parameters.