Based on the Cusp Catastrophe to Research the Relationship among Traffic Flow Three Parameters

The kick phenomenon is often appeared in practical traffic flow. And it is hard to be explained through the traditional traffic flow three parameters models. On the basic of this, it is essential to research relationship among traffic flow three parameters by cusp catastrophe model. The measured data, which consist of the information of velocity, density and flow, is divided into groups to be fitted. And based on the relationship among systems, potential function can be built up. So the relationship between velocity-density, velocity-flow and flow-density are analyzed respectively. The result of theoretical analysis is conformed to the practical data. Because of measured data, which is detailed, this method is of definite practical applied value.