Optimization model for regional green wave coordinated control based on ring-and-barrier structure.

It's often hard for existing mathematical models to unify and optimize all control variables including phase time, signal phase sequence, offset and signal cycle at the same time. An optimization model for regional green wave coordinated control based on Ring-and-Barrier structure under unsaturated signalized network is proposed in this study. The constraints of signal timing parameters, such as signal cycle, signal phase sequence and phase time, are explored for the intersections based on Ring-and-Barrier structure. It is proved that the comprehensive optimization of phase time and signal cycle, signal phase sequence and offset can be achieved. And a three-dimensional time-space diagram is innovatively proposed to display the regional green wave coordinated control effect. The coordination effect of the model proposed in this paper is compared with the coordination effect of Synchro via a case study. It demonstrates that the regional signal timing scheme obtained by this model can lead to a better result in all aspects of each intersection, each artery and the whole control area. In the meanwhile, the proportion of bandwidth at each intersection is wider than 79% while satisfying the minimum demand of traffic flow at each intersection. To sum up, this model can improve the overall optimization effect of regional signal coordination control by optimizing the phase time, and achieve the comprehensive optimization of signal cycle, signal phase sequence, offset and phase time. [ABSTRACT FROM AUTHOR]