An Improved Cellular Automaton Model for Traffic Flow

A cellular automaton model for traffic flow with crossings controlled by traffic-polices is proposed. The simulations reveal that there are qualitative distinguishes between traffic flow models with and without polices. In the cellular automaton models with traffic-polices, the free flow phase occurs at a much lower car density, and the characteristic of the first-order transition disappears, and two second-order transitions come forth, and jamming phase moves towards higher concentrations, and thus traffic performances are dramatically improved. It is shown that the traffic flow model with traffic-polices conforms with the realistic traffic.