Investigation of the Relationship between Traffic Hysteresis and String Stability of Vehicle Platoons

Abstract

Traffic oscillations deteriorate traffic safety and efficiency. Relevant to those oscillations, traffic hysteresis and string stability of platoons of vehicles have been extensively studied. However, the relationship between these two remains underexplored, leading to deficits in knowledge about the effect of regulating one on the other. The present paper investigates the correlation between string stability and traffic hysteresis and their possible trade-offs. The two are quantified based on trajectories that are extracted by simulation experiments and by real-world data. A strong correlation between string stability and traffic hysteresis is found. In the case of instability, hysteretic platoons are identified almost every time. It suggests that instability is one of the leading causes of hysteresis, although other factors also play a role since hysteresis loops have also been detected in string stable platoons.