设置自动驾驶小客车专用车道的六车道高速公路交通流特性

Traffic flow characteristics of six⁃lane freeways with a dedicated lane for automatic cars

为解决未来高速公路上自动驾驶小客车(AC)、人类驾驶小客车和人类驾驶大货车混行所带来的安全和效率问题,研究了在六车道高速公路上设置AC专用车道的方法及其对交通流的影响。提出了内侧式AC专用车道的隔离方式和出入口布设方法。基于VISSIM建立了包含入口和出口匝道的高速公路模型、车辆模型和驾驶行为模型,高速公路设计速度取120 km/h,货车混入率取0.2。通过模拟实验,研究了设置内侧式AC专用车道后AC渗透率和AC安全车头时距对交通流特性的影响,探讨了AC专用车道对各车型和各车道运行的影响。结果表明:AC渗透率对交通流特性的影响是显著的和非线性的,存在一个最优AC渗透率,使设置了AC专用车道的高速公路具有最大的通行能力、临界密度和平均速度;AC安全车头时距对交通流特性的影响是非线性的,AC安全车头时距越小,对高速公路通行能力的改善效果越显著;AC渗透率对各车型和各车道的流量和平均速度都有显著影响,对AC流量和内侧车道流量的影响最大。

In order to solve the safety and efficiency problems caused by the mixed operation of automatic cars(AC),human-driving cars and human-driving trucks on freeways in the future,the method of setting an AC dedicated lane on six-lane freeways and its impact on traffic flow are studied.The separation mode and the entrances and exits layout method for inside AC dedicated lane are proposed.The models of vehicles,driving behaviors and freeway sections with entrance and exit ramps are established based on VISSIM.Through simulation experiments in which the freeway design speed is 120 km/h and the truck ratio is 0.2,the effects of AC penetration rate and AC safe headway on traffic flow characteristics after setting an AC dedicated lane are studied,and the effects of the AC dedicated lane on the operation of each vehicle type and each lane are discussed.The results show that the influence of AC penetration rate on traffic flow characteristics is significant and nonlinear;There is an optimal AC penetration rate,which can maximize the capacity,critical density and average speed of the freeway with an AC dedicated lane;The influence of AC safe headway on traffic flow characteristics is nonlinear;The smaller the AC safe headway,the more significant the improvement effect on freeway capacity;The AC penetration rate has significant impacts on the flow rate and average speed of each vehicle type and each lane,especially on the flow rate of AC and inside lane.