A hybrid strategy for real-time traffic signal control of urban road networks

Abstract

The recently developed traffic signal control strategy, TUC, (Traffic-responsive Urban Control) requires availability of a fixed signal plan that is sufficiently efficient in undersaturated traffic conditions. To drop this requirement, the well known Webster procedure for fixed signal control derivation at isolated junctions is employed appropriately for real-time operation based on measured flows. It is demonstrated via simulation experiments and field application that: (a) The developed real-time demand-based approach is a viable real-time signal control strategy for undersaturated traffic conditions; (b) it can indeed be used within TUC to drop the requirement for a pre-specified fixed signal plan; (c) it may, under certain conditions, contribute to more efficient results compared with the original TUC method.