Analysis on Traffic Flow Breakdown from Vehicular Traffic Movement

Being based on the traffic flow breakdown appeared when the best density near Km being reached in the traffic-flow-density model,in this paper,the flow-time change law and the density-time change law around the best density of the moving vehicular traffic flow have been analyzed,which has shown that the velocity echo generated from the moving traffic flow is a major factor for the traffic flow breakdown. Based on the analysis on the nature of the defect of Greenhill model,in this paper,the necessity of using two-stage model for traffic flow model has been pointed out and the corresponding model has been established.