Evaluation of Driver’s Careless State in Traffic Flow with Mixed ACC Vehicles

Abstract

The development of autonomous driving technology is pushed forward rapidly to improve the safety and smoothness of road traffic. In a previous study, focusing on adaptive cruise control (ACC) system, we simulated mixed-traffic flow consisting of ACC vehicles and non-ACC vehicles, and evaluated the safety and smoothness of the traffic flow and drivers’ behaviors. In the results of this study, it has been confirmed that the smoothness of traffic flow was improved with the increase of the mixture ratio of ACC vehicles, and that driver’s stress could be relieved by the ACC vehicles being mixed. This study assumes that a driver can become easily careless when the driver's stress is extremely reduced. Based on the assumption, the driver's viewpoint movement and reaction time was analyzed to evaluate the driver's carelessness. As a result, it has been confirmed that a driver can become possibly careless in the environment where many ACC vehicles are driven even when driving a non-ACC vehicle. It has also been confirmed that driving an ACC vehicle can cause a driver's arousal level to be lower, if not cause him or her to drive carelessly.