To study the impact of on/off-ramps on traffic stability in heterogeneous traffic flow, a novel lattice hydrodynamic model was presented. The new model’s stability condition was determined using the linear stability analysis method. The theoretical results reveal that traffic flow stability is influenced by the proportion of vehicles with different maximum speeds and safe headway, as well as the presence of on-ramps and off-ramps to a certain degree. Through the approximate perturbation method, the mKdV equation and the kink–antikink solution of the traffic density at the jam area are obtained. In order to verify the effectiveness and feasibility of the new model, numerical simulations were conducted to demonstrate on/off ramp effect and different proportions of vehicles which possess bigger maximum velocity or safe space headway affect the traffic stability. The numerical results indicate that in heterogeneous traffic flow scenarios, increasing the ratio of vehicles which possess bigger maximum velocity or bigger safe space headway can lead to a deterioration of traffic stability. The effect of on-ramp could cause traffic instability, while the effect of off-ramp is beneficial for easing traffic congestion.

为了研究异构交通流中入口/出口匝道对交通稳定性的影响，提出了一种新颖的晶格流体动力学模型。采用线性稳定性分析方法确定了新模型的稳定性条件。理论结果表明，不同最高车速和安全车头时距的车辆比例以及入口匝道和出口匝道的存在在一定程度上影响交通流稳定性。通过近似摄动法，得到了拥堵区交通密度的mKdV方程和扭结-反扭结解。为了验证新模型的有效性和可行性，通过数值模拟验证了进出匝道效应以及最大速度或安全车距较大的不同比例车辆对交通稳定性的影响。数值结果表明，在异构交通流场景下，增加最大速度较大或安全间距较大的车辆比例会导致交通稳定性恶化。入口匝道的影响可能会导致交通不稳定，而出口匝道的影响则有利于缓解交通拥堵。