INTEGRATED TRAFFIC CONTROL FOR FREEWAYS USING VARIABLE SPEED LIMITS AND LANE CHANGE CONTROL ACTIONS

The wide deployment of Vehicle Automation and Communication Systems (VACS) in the following decade is expected to influence traffic performance on freeways. Apart from safety and comfort, one of the goals is the alleviation of traffic congestion that is a major and challenging problem for modern societies. This paper investigates the combined use of two feedback control strategies utilizing VACS in different penetration rates, aiming at maximising throughput at bottleneck locations. The first control strategy employs mainstream traffic flow control using appropriate variable speed limits as an actuator. The second control strategy delivers appropriate lane-changing actions to selected connected vehicles using a feedback-feedforward control law. Investigations of the proposed integrated scheme have been conducted using a microscopic simulation model for a hypothetical freeway featuring a lane-drop bottleneck. The produced results demonstrate significant improvements even for low penetration rates.