Automatic Vehicle-Following

Abstract

Vehicle following and its effects on traffic flow has been an active area of research. Human driving involves reaction times, delays and human errors that affect traffic flow adversely. One way to elliminate human errors and delays in vehicle following is to replace the human driver with a computer control system and sensors. The purpose of this paper is to come up with a control system for automatic vehicle following, examine its effect on traffic flow and compare its performance with that of the human driver models. We proposed a control law for automatic vehicle following that is not cooperative i.e. it does not exchange information with other vehicles and yet is free of oscillations and slinky-effects. The ellimination of the slinky-effect is achieved by using a safety distance separation rule that is proportional to the vehicle velocity (constant time headway). The performance of automatic vehicle following is found to be superior to that of the human driver models considered. It has a faster and better transient response that leads to a much smoother and faster traffic flow. Traffic flow rates can be improved considerably with automation due to the ellimination of human delays and errors and the potential of using smaller and safer intervehicle spacings than those assumed by human drivers.