三车道宏观交通流模型和扰动演化的数值研究

随着城市交通设施的完善，多车道在城市高速路交通中变得比较普遍. 三车道的出现使车辆变道易于实现，这就增加了交通问题的复杂性. 采用宏观交通流理论，建立了一种允许车辆变道的单向三车道连续交通流模型，以及与之相容的差分离散格式. 数值模拟了初始密度、扰动强度、初始扰动范围等因素对扰动传播和发展演化的影响. 结果显示:扰动波的传播方向和传播速度主要由初始未扰动车流密度大小决定；初始扰动范围的大小对扰动波幅值变化的影响比较大；某一条车道发生的扰动是否会影响其他车道，则受初始车流密度和扰动强度大小两个条件影响；在中等密度多车道交通流中，扰动波的发展过程呈现出复杂的非线性特征，数值格式的选择比单车道更加困难. 

A MACRO TRAFFIC FLOW MODEL WITH THREE LANES AND NUMERICAL STUDY

With the development of traffic infrastructure,multi lanes become common in city freeways. Because vehicles can change lanes in multi lanes,new traffic problems have appeared.In the present paper, a continuous traffic flow model for the unilateral three lanes systems and its different discretization schemes are developed based on the macro traffic flow theory associated with the lane changing of vehicles.Numerical study on the propagation and development of traffic disturbance is carried out with the differ...