Roadway traffic controller design for automated highway systems

Abstract

For manual driving, the traffic flow is often irregular, unstable leading to congestion and to low traffic flow rate during minor incidents. These irregularities are due to variation of vehicle speeds and headways that are selected by the individual drivers. It is expected that the congestion could be reduced and traffic flow rate could be increased, if the speed and density of the vehicles along a lane can be properly controlled by a roadway controller. In this paper we propose a roadway controller and investigate the benefits of controlling the density and speed of the vehicles along a lane by using the proposed roadway controller. The roadway controller sends the appropriate speed commands to vehicles in each section of the lane. The vehicles are equipped to follow each other automatically and respond to the roadway commands without any driver intervention. A macroscopic traffic flow model is used for analysis and simulations. Our results demonstrate significant benefits in terms of smooth and stable traffic flow that reduce congestion considerably.