Abstract: In order to overcome the deficiency of the classical Optimal Velocity（OV） model adjusting the optimal velocity only by the distance, an improved Optimal Velocity Difference（OVD） model is proposed by taking the effects of the preceding and following vehicle’s optimal velocity difference on the stability of traffic flow into account. Then, the model’s stability condition is analyzed and deduced using the small vibration amplitude disturbance method. Finally, the simulation analysis of the OVD model is conducted. Through the linear stability analysis, it can be found that the critical drivers’ reaction sensitivity coefficient is reduced, obviously the stability region is apparently enlarged after considering the optimal velocity difference between preceding and following vehicles. Simulation results show that compared with the OV model, the improved OVD model is able to notably improve the stability of traffic flow under the same initial disturbance conditions.

Key words: traffic flow, OV model, Optimal Velocity（OV）, car-following model, stability analysis

摘要： 为了克服经典最优速度（OV）模型仅依据车间距单一因素调整跟驰车最优速度的局限性，在考虑前导车与跟驰车最优速度差信息对交通流稳定性影响的基础上，提出了一种改进的最优速度差（OVD）模型，并通过小振幅摄动法对模型进行了稳定性分析，推导了模型的稳定性条件。最后对改进OVD模型进行了数值仿真。通过线性稳定性分析，发现考虑前后车辆最优速度差后，自由流稳定的临界驾驶员反应灵敏度系数明显减小，稳定区域显著增加。仿真结果表明，与OV跟驰模型相比，在相同初始扰动条件下，改进OVD模型能够明显增强交通流的稳定性。

关键词: 交通流, 最优速度（OV）模型, 最优速度, 跟驰模型, 稳定性分析