Modeling Car-Following Behavior In A Connected Environment And Analysis On Traffic Flow Stability

With the development of economy,the number of motor vehicles has increased a lot.Traffic jam becomes serious increasingly.The introduction of VANET(Vehicle Ad hoc NETwork)makes drivers capable of obtaining driving information of neighboring multiple vehicles.This provides the opportunity to improve the stability of traffic flow and ease congestion.As the most basic microscopic driving behavior,car-following model is the basis of research of the traffic flow theory.Although the study of modeling regular car-following behavior has been very mature,these models can’t describe the traffic rules in a connected environment accurately.Based on the existing car-following model,an extended model is presented to describe the acceleration behavior of connected vehicle.As well,stability condition is derived and numerical simulations testify to the theoretical analysis.The main contents are as follows:(1)Based on the BLVD(Backward Looking and Velocity Difference)and the OVCM(Optimal Velocity Changes with Memory)model,considering the driving information of multi-preceding vehicles can be accurately obtained by V2 V technology as well,a new model is proposed by taking account of multi-preceding vehicles’ optimal velocity changes and backward looking effects(BL-MOVCM).(2)The linear stability analysis is conducted to derive the stability conditions of the model.By using nonlinear analysis,the mKdV(modified Kortewege-de-Vries)equation around the critical point is obtained.The phase diagram of the traffic flow can be divided into stable,metastable and unstable regions.It is shown that the stable area of BL-MOVCM model is significantly enlarged,compared with FVD model,BLVD model and OVCM model.(3)By using numerical simulation,the stability performances which include vehicle start-up,stop and evolution process of BL-MOVCM,OVCM,BLVD and FVD model are verified.The simulation result of heterogeneous traffic flow shows that the traffic flow stability is enhanced with the increase of market penetration rate of connected vehicles.In conclusion,both theoretical analysis and simulation results show that taking into account multi-preceding cars’ optimal velocity changes and backward looking effects by V2 V technology can enhance the traffic flow stability and ease congestion.The results of this study have a directive sense in designing a connected cruise control system.