Researching the brittleness of traffic system based on cusp catastrophe model

Brittleness is one of properties of complex system. And traffic system is a complex system. Velocity, flow and density are considered as subsystems of the whole traffic system. The research object is the highway traffic system. The qualitative analysis of traffic system is given on the basis of catastrophe theory. And the quantitative analysis of traffic system is given based on the cusp catastrophe mode. The relative results are also got. The results of analysis are conformed to the reality. The brittleness analysis of traffic system is given by combining the result of the quantitative analysis with complex system brittleness theory. Thereby the policy and measure of traffic control must be done when the observed density of practical traffic flow is nearby the critical density.