交通事故下高速公路有效通行能力分析与估算

Analysis and Estimation on Expressway Actual Capacity under Traffic Accidents

高速公路发生交通事故后,事故车辆占用车道,必然造成道路交通瓶颈,降低高速公路实际通行能力。为了定量地分析交通事故对高速公路通行能力造成的影响,建立VISSIM仿真的高速公路典型路段交通事故模型,并提出以折减系数法为基础的交通事故下高速公路有效通行能力计算模型。分析不同阻塞车道数、阻塞车道长度、大车比例和交通事故持续时间下,交通事故点断面流量随时间的变化规律。研究结果表明:高速公路通行能力随阻塞车道数的增加、阻塞车道长度的增长、大型车占有率的增大而减小。而当通行能力刚好满足交通量需求时,道路通行能力几乎不受交通持续时间影响;运用VISSIM仿真模型得到基本通行能力的高速公路有效通行能力折减参数,其中当阻塞车道长度为0.1 km时,折减系数为0.808。

After a traffic accident happened onto the expressway,the accident vehicle occupied the expressway lane,causing traffic bottlenecks and reducing the expressway capacity.In order to quantitatively analyze the impact of traffic accidents on expressway capacity,a classical traffic accident model of expressway was established based on VISSIM simulation,and a calculation model of traffic capacity of expressway was proposed under traffic accident based on reduction coefficient method.The variation regularity of the cross-section traffic flow with time is analyzed,under different blocking lane numbers,closed lane length,the proportion of large big vehicles and the traffic accident duration.The results show that,the expressway capacity decreases with the increase of the number of blocked lanes,the length of closed lanes and the increase of the share of large car shares.When the traffic capacity just meets the traffic demand,the traffic capacity is hardly affected by the traffic duration.In addition,the VISSIM simulation model is used to obtain the effective traffic capacity reduction parameters of expressways based on the design capacity,the result shows that when the closed lane length is 0.1 km,the reduction coefficient is 0.808.