Traffic-responsive signals combined with perimeter control: investigating the benefits

Empirical and research evidence suggests that traffic-responsive signal control strategies are generally not as efficient in over-saturated traffic conditions characterized by queue spillbacks. Recent studies on (MFD/NFD) have identified a destabilizing gridlock process that arises in congested networks which precludes efficient operation. The MFD has also been used to develop urban traffic control solutions (e.g. perimeter or gating control) to avoid congestion. The purpose of this paper is to explore the benefits of combining gating with locally adaptive traffic signals through micro-simulation of the Chania, Greece traffic network. Two adaptive traffic signal strategies are considered with the perimeter control strategy. The results of the combined gating/adaptive signal control scheme are compared to gating under fixed traffic signals and the implementation of adaptive signals only. The convincing outcome of this simulation study motivates the real-field implementation of gating/perimeter control in the cities, without even changing the existing adaptive control strategies.