Abstract: City traffic system is a very complicated non-linear system. It's very difficult to build precise mathematical model and BP neural network has advantage in self-study and self-adaption. In this paper, for the control problem in one intersection, based on improved BP neural network algorithm, considering key traffic flow and nonkcy traffic flow, hierarchical weighted neural network controller was proposed and desiged. It's used to control traffic on time. The simulation results show that this control method is better than traditional methods.

Key words: Traffic control,Neural network,Key traffic flow