Study On The Modelling Of Complex Dynamic Properties Of Traffic Flow And Numerical Simulation

With the rapid development of economy,the increasingly serious traffic congestion has become an important factor restricting the development of large and medium-sized cities.The research of traffic flow models and theory can not only help to deepen the understanding of the law of traffic system operation,but also act as theoretical guidance for transportation planning management and control,and moreover,can provide theoretical basis for the test of advanced transportation system and technology.Therefore it is of great significance in theory and practice to study the modelling of complex dynamic properties of traffic flow.In a connected vehicle environment,a driver can use the movement information of some adjacent vehicles to anticipate and adjust the velocity of his own vehicle.By using such multi-anticipation driving strategy,every vehicle in the system can cooperate with its adjacent vehicles to run in a queue,which helps to ease traffic congestion and increase road capacity.The reaction-time delay of drivers is unavoidable.Therefore the introduction of the reaction-time delay of drivers in the traffic flow models can better describe the real traffic flow characteristics.In the actual traffic,it is common that the traffic is mixed by multi-lane road and multi-class vehicles.Thus,the research of multi-lane models and multi-class models is necessary in order to describe the actual traffic flow more accurately.Several novel traffic flow models are constructed by considering the multi-anticipation driving strategy,reaction-time delay of drivers or multi-lane traffic,and the proposed models are investigated based on the theoretical analysis and the simulations of dynamic properties.Moreover,a high-resolution numerical method for solving the multi-class LWR(Lighthill-Whitham-Richards)model is investigated.The main work is as follows:1.Based on the forward-looking driving strategy,the multi-anticipation delayed models are constructed to simulate the complex dynamic characteristics of the traffic flow in a connected vehicle environment,and the stability analyses are conducted for the novel models.A multi-anticipation delayed car-following model is constructed by introducing the reaction-time delay of drivers and considering the use of the unbalanced information about headways and velocity differences between multiple adjacent vehicles in front of the current vehicle.The results of numerical simulations demonstrate that it is necessary to unevenly use information of headways and velocity differences of front vehicles in order to introduce variables as few as possible.Another multi-anticipation car-following model is proposed by introducing the reaction-time delay of drivers and the multiple velocity differences between the current vehicle and the preceeding vehicles.The numerical results show that appropriate introduction of multiple velocity differences can enhance the stability of traffic flow,and can ease the traffic congestion to a certain extent.A multi-anticipation lattice hydrodynamic model is presented by taking into account drivers’ reaction-time delay and multi-anticipation driving strategy.The simulating results show that the unfavorable impact caused by the reaction-time delay on the stability can be partly compensated by introducing more lattices in the model.The three constructed multi-anticipation delayed models can provide the basic models for the traffic flow simulation of cooperative driving in the network environment.2.In the connected vehicle environment,a multi-anticipative car-flowing model is constructed based on the driving strategy of the bidirectional perspective.The obtained model is extended to a macro model.The stability condition and local cluster effect are investigated for the macro model via the theoretical and numerical methods,respectively.The simulation results are consistent with the results of the stability analysis,which confirms the rationality of theoretical analysis.The novel macro model of the bidirectional perspective can be used as the basic model to simulate the traffic flow by the macro way in the connected vehicle environment,which helps to study the construction and expansion of infrastructure and formulate macro management measures.3.An extended transfer flow rate is proposed to mimic the lane-changing behavior.A new three-lane lattice hydrodynamic model is presented.The stability condition of the model is derived by applying the linear stability method.For the case of small disturbance,the behavior of the lane changing is investigated.The results show that the extended transfer rate and the improved model are rationality.The new three-lane lattice hydrodynamic model can be a basic model for simulation traffic flow to investigate the lane-changing behavior in mixed traffic.4.The non-oscillatory central scheme is extended to the multi-class LWR traffic flow model.A high-resolution numerical method for solving the model is presented.The discrete slopes and the spatial derivative of the flux are approximated by a nonlinear limiter to guarantee the non-oscillatory behavior and to avoid the computation of the Jacobian.The resulting method has the advantages of simple form,small computation and high resolution.The results of numerical experiments demonstrate the efficiency of the method.