Properties of Traffic Flow under a New Boundary Condition

We study the properties of traffic flow coming from free flow to congested flow on a two-lane road by using cellular automaton traffic model. A new boundary condition is proposed, which exhibits the reason of the relation that traffic flow against on the injected probability. The simulation results show that the traffic never comes into congestion even if there are enough high injected probabilities, unless there is improper lane changing or the complete open boundary is destroyed. As a consequence, some lane changing mode discussed in this paper is notably efficient in easing traffic congestion inducing by the accident or ramp flow downstream as well as no need to restrict the inflow upstream.