路网环境下考虑大型车混入率的事故疏散诱导模型

大型车的混入对高速公路交通流产生了较大的影响，尤其是在交通事故情景下。为了引导事故条件下驾驶人和组织者做出高效准确的决断，将考虑了大型车混入率的动态空间占有率模型引入到交通波模型，构建干涉与非干涉情景下的交通事故影响模型。以郑尧高速为例，对模型的准确性和可行性进行了验证，分别对干涉情景下的疏散时间、疏散量以及事故发生的位置，车辆数等指标与事故影响程度的指标（包含事故最远排队长度，事故持续时间）关系进行分析。研究结果表明：疏散时间与事故影响程度成正相关关系，疏散量与事故影响程度成负相关关系，而事故发生点与上游匝道之间的距离与其关系不大；道路服务水平为0.456，车辆数为1 321 veh·h^-1时，为了使得分合流区不受影响，在不采取任何措施的情景下，应将大型车混入率控制在50.1%以下，使得最远排队长度在10 km内；当大型车混入率大于58%时，将很难通过干涉引导避免对上游分合流区产生影响；在35 min以内采取干涉措施的效果最为明显，而大于35 min时，事故持续时间会发生一个急剧的增加，不利于路网恢复，之后事故恢复时间将趋于平稳；对道路交通量进行模拟可知交通量每增加50 veh，疏散时间和距离增加的范围为1.5 min，3.6 min]和1.209 km，1.543 km]。研究结果可为高速公路事故诱导策略制定和疏散效果提升提供参考。

An Accident Induction and Evacuation System Considering the Mixing Rate of the Large Vehicles Under the Freeway Network

The mixing rates of large vehicles strongly affect the traffic flow in a freeway, especially during an accident. To provide guidance that can help drivers and emergency personnel deal with accidents efficiently, this study added the dynamic space occupancy model, which considers the mixing rate of large vehicles, to the traffic wave model, and constructed an accident influence model with and without intervention. Taking an accident that occurred in the Zheng-Yao freeway as an example, the accuracy and feasibility of the model were verified. The relationships between several factors (i.e., evacuation time, evacuation volume, accident location, and traffic flow) and two indices (i.e., maximum queue length and recovery time) were analyzed. The results show a positive correlation between the evacuation time and impact of the accident; a negative correlation between the evacuation volume and degree of influence the accident; and weak correlation between the distance from the accident point to the upstream ramp and the degree of influence of the accident. The service level of the freeway is 0.456, and the number of vehicles is 1 321 veh·h^-1. To prevent the accident from affecting traffic on the upstream ramp, the mixing rate of large vehicles should be controlled to less than 50.1% to ensure that the maximum queuing length is within 10 km. If it exceeds 58%, the intervention cannot effectively prevent traffic on the upstream ramp. It is better to apply interventions when the evacuation time is less than 35 min. If it exceeds 35 min, the accident recovery time will rapidly increase, which hinders network recovery. Then, this trend will tend to stabilize. The simulation results showed that when the traffic flow increased by 50 vehicles, the increasing ranges of the recovery time and the maximum queue length are about1.5 min, 3.6 min] and1.209 km, 1.543 km], respectively. The research results can serve as a reference for the formulation of freeway accident induction strategies and the improvement of evacuation outcomes.