Feedback Traffic Control at Highway Work Zones using Variable Speed Limits

Abstract

This paper presents a novel real-time merging traffic control approach for throughput maximization at highway work zones using Variable Speed Limits (VSL). A Proportional-Integral (PI) feedback regulator is employed for control which is simpler and potentially more robust compared to heuristic or optimal control procedures. Practical VSL implementation aspects have been taken into account. The proposed concept is demonstrated and evaluated using a validated microscopic traffic flow model for a real motorway work zone in Germany. Remarkable improvements can be observed for all performance indexes considered and for all replications simulated. Investigations have been carried out for different compliance rates, different set points utilized by the feedback regulator, as well as for different values of the lower admissible bound of the VSL. The proposed approach is deemed suitable for field implementation.