Impact of Cooperative Systems on Drivers’ Car-Following Behavior

In-vehicle technologies and co-operative services are designed to ultimately reduce congestion and increase traffic safety. This paper investigates the impact of an infrastructure-to-vehicle co-operative system on drivers’ car-following behavior. Car following behavior, which describes the behavior of a vehicle while following the vehicle in front of it, has a significant impact on traffic performance, safety, and air pollution. In addition, it is an essential component of microsimulation models. Twenty nine test drivers drove an instrumented vehicle twice with and without the system. Trajectory data of each vehicle and the vehicle in front were collected. Car-following models were estimated for both cases, with and without the system, and the results of the two models were compared. The results show that co-operative systems have a positive impact on drivers’ car-following behavior. The system harmonizes the driving behavior of drivers and reduces the range of acceleration and deceleration differences among them. The impact of the system is larger on older drivers compared to younger drivers.