Traffic flow study for a modified car-following model based on dynamical safety headway

Abstract

A modified optimal velocity with dynamical safety headway is introduced based on the optimal velocity car-following model. The dynamical safety headway relates to vehicle’s velocity compared to the constant safety headway. To study the influence of dynamical safety headway on the car-following performance, theoretical analysis and numerical simulation of the optimal velocity car-following model with dynamical safety headway are carried out. With the stability analysis method in control theory, a linear stability condition is obtained for the new model. In addition, the car-following performances of traffic flow evolution rules, traffic capacity properties and vehicle starting features of the new model are exhibited through numerical simulation. The results show that the dynamical safety headway is more efficient than the constant safety headway in improving traffic stability, enhancing traffic capacity and shortening the vehicle starting time in the car-following process. It concludes that the dynamical safety headway is a better strategy compared to constant safety headway in real car-following control.