Simulation of the penetration rate effects of ACC and CACC on macroscopic traffic dynamics

Abstract

A macroscopic approach modeling the penetration rate of Adaptive Cruise Control (ACC) and Cooperative Adaptive Cruise Control (CACC) vehicles and its effect on traffic dynamics is investigated. Modeling is based on the introduction of a relaxation term in a gas-kinetic traffic flow (GKT) model that satisfies the time-gap principle of ACC or CACC systems and allows for consideration of mixed traffic of manual and ACC/CACC vehicles. The relaxation time is assigned to multiple leading vehicles in the CACC case; whereas in the ACC case only relates to the direct leading vehicle. Numerical simulations investigate the effect of the penetration rates of ACC and CACC equipped vehicles to traffic flow macroscopic stability, with respect to perturbations introduced in a ring road, and to flow characteristics in an open freeway with merging flow at an on-ramp.