混合网联环境快速路交织区交通流特性分析

Analysis on the characteristics of traffic flow in expressway weaving area under mixed connected and autonomous environment

在混合人工驾驶车辆(human-driven vehicle, HV)与网联自动驾驶车辆(connected and autonomous vehicle, CAV)的交通流环境下,为提升快速路交织区的通行效率与行车安全性,深入分析了混合交通流的基本特性.首先,结合交织区通行能力计算模型,研究交织区域长度、交织交通量比和CAV渗透率等因素对交织区通行能力的影响;其次,推导混合交通流基本图模型,并在不同期望车头时距和CAV渗透率下对混合交通流基本图参数进行分析;最后,通过数值仿真实验,分别探讨在由车辆换道行为所产生的单一扰动和频繁扰动条件下,混合交通流行驶速度与车头间距的时空演化规律及交通流稳定性.结果表明:CAV渗透率的提升可以提高交织区通行能力以及混合交通流交通效率;交织交通量比的减小和交织区域长度的增大可提高交织区通行能力;提升CAV渗透率可以有效提高混合交通流的稳定性,但较小的车头间距也会造成一定的安全隐患.

In the traffic flow environment composed of human-driven vehicles(HV) and connected and autonomous vehicles(CAV), in order to improve the traffic efficiency and driving safety of expressway weaving area, the basic characteristics of mixed traffic flow are analyzed in depth. Firstly, combined with the traffic capacity calculation model of weaving area, the influence of weaving area length, volume ratio and CAV permeability on the traffic capacity of weaving area is analyzed. Secondly, the fundamental diagram model of mixed traffic flow is derived, and the parameters of the mixed traffic flow fundamental diagram are analyzed under different expected headways and CAV permeabilities. Finally, through numerical simulation experiments, the temporal and spatial evolution of mixed traffic flow speed and headway and the stability of traffic flow are discussed under the conditions of single disturbance and frequent disturbance caused by vehicle lane changing behavior. The results show that the increase of CAV permeability can improve the traffic capacity of weaving area and the traffic efficiency of mixed traffic flow. The decrease of volume ratio and the increase of weaving area length can improve the traffic capacity of weaving area;increasing CAV permeability can effectively improve the stability of mixed traffic flow, but a small headway can also cause certain security risks.