title: Cellular automata model simulating traffic interactions between on-ramp and main road.
abstract: In this paper, we study the on-ramp system using the cellular automata traffic flow model. Different from previous works, we consider not only the influence of the on-ramp flow on the main road but also the opposite influence. The update rules are given in detail and the concept of priority is introduced. The numerical simulations are carried out and the phase diagram is presented. Two different types of phase diagram are distinguished and the currents of the on-ramp system are discussed.