Study On The Formation Mechanism,Characteristics And Control Of Traffic Congestion Induced By Road Bottleneck

With the development of the times,the improvement of the national economy and the rapid increase of the number of cars,traffic congestion has become increasingly serious.Road bottleneck is the direct cause of most traffic congestion.Traffic congestion brings many social,economic and environmental problems.In order to solve the traffic congestion problem,it is necessary to study the mechanism,characteristics and control scheme of traffic congestion.Based on the microscopic and macroscopic models of traffic flow,this paper studied the formation mechanism of congestions induced by traffic bottlenecks,the characteristics of traffic congestion and the control methods to solve traffic congestion.The main research work of this paper is as follows:(1)Based on the two-lane lattice hydrodynamic model(LH model),the partial reduced-lane LH model(PRLH model)is proposed.We carried out the numerical simulation on the model,and obtained various traffic congestion patterns,such as homogenous congested traffic,homogenous synchronized traffic,pinned localized cluster,moving localized cluster,stop-and-go waves and oscillatory congested traffic,caused by traffic bottlenecks on the partial reduced lane.The key parameters that induce various traffic congestion patterns are obtained by numerical simulation.The simulation results reflect the feasibility of the model to predict traffic congestion.(2)A full angular velocity difference model(FAVD model)is proposed by introducing angular velocity and displacement on curved road.The macroscopic model of the curved road is deduced from the microscopic model.The linear stability and non-linear analysis for the model are carried out.The linear stability conditions and the solutions of traffic density wave described by KdV-Burgers equation are obtained.Through numerical simulation,the traffic congestion behaviors on the curved road are revealed.Simultaneously,the simulation shows that the radius and sensitivity coefficient of the angular velocity difference have an important influence on traffic congestion,and the phenomenon of local clustering is also found in the simulation.(3)On the basis of optimal velocity model(OV model),a time-delayed velocity difference model(TDVD model)is proposed.Linear stability analysis and Hopf bifurcation analysis of the model are carried out,respectively.It is found that traffic instability corresponds to Hopf bifurcation.The critical points of Hopf bifurcation are also found.(4)Based on the optimal velocity model(OV model),we construct a feedback control model by presented the Optimized Acceleration Feedback Control method(OAFC method).The transfer function of the control system is obtained by Laplacian transformation of the model.According to the control theory,when the norm of transfer function Hx is less than 1,the system is stable and the global stability condition is obtained.The theoretical analysis of control scheme is validated by numerical simulation.Results indicate that traffic jams are effectively suppressed by OAFC method.Finally,the full text is summarized and prospected.