Research On The Brake Light Cellular Automaton Model Of Traffic Flow

With the fast growth of the economic,the transportation engineering,one of the significant section of the development,have always encountering varies society problems,including excessive ownership of private cars,the insufficient road facilities,the air pollutions and the energy wasting,etc.Investigations into the features and evolution rules of traffic flow can generate some reliable suggestions on road planning,traffic management and optimization to a large extent.Traffic flow modeling is nowadays a mainly section of traffic flow researches,and the roles of model are greatly lying on whether it could describe empirical traffic flow characteristics or not.The traffic breakdown,one of the significant empirical phenomena of traffic flow,have a large impact on real traffic optimization and control.On an empirical observation,Kerner characterized the congested flow into synchronized flow and wide moving jam,and the transition from the free flow to synchronized flow is traffic breakdown.After traffic breakdown,the traffic flow would evolve to widening synchronized pattern(WSP),moving synchronized pattern(MSP),localizing synchronized pattern(LSP)or general pattern(GP).However,most up-to-date traffic flow models cannot able to reproduce empirical consistent synchronized flow,let alone the traffic breakdown.The brake light models,as one of main cellular automaton traffic flow models,have been widely applied.However,the desired time gap brake light model(DTGBLM)proposed recently is not able to reproduce empirical downstream front speed of synchronized flow pattern,which would weak its ability to predict the traffic flow state after the traffic breakdown.In this paper,we proposed a new cellular automaton model on the base of DTGBLM analysis,and the improvements are as follow:(1)the drivers would be sensitive to the brake light only when their speeds are larger than a critical speed;(ii)the anticipated deceleration of a preceding vehicle increases with the increase of the speed of the following vehicle.Simulation analysis shows that the new model can depict traffic breakdown and related synchronized traffic flow patterns.Importantly,it can realistically reproduce the propagation speed of downstream front of the MSP.Finally,we generated simulations on a two-lane road system with two different symmetric lane change rules.The results show that our new model is able to reproduce empirical traffic flow phenomena,although different lane change curves are drawn.Furthermore,the mixture traffic flow simulation cause the plug,which is eliminated after we altering the lane change rules of the slow vehicles.