Abstract: Two influential traffic flow models formulated by Zhang H M and Wu Zheng are improved to include the lane-change problem,and the relations between the two models and the traditional speed-density hypothesis model are discussed.Runge-Kutta Discontinuous Galerkin Finite Element Method is generalized and applied to these three models for numerical solutions through which the traffic signal problem,lane-change problem and non-equilibrium traffic flow phenomena are well simulated.