Optimally coordinated freeway traffic control for networks containing bottlenecks with capacity drop and hysteresis behaviour is considered. Because of the multitude of traffic jams and the spatial and temporal relationships between control actions and traffic behaviour, this problem is not as straightforward as that for local control. The order in which the measures are applied may be relevant, or it may be possible that not all jams can be resolved. In that case the best possible locations of jams should be determined. An approach to address these problems is developed in which a generalized representation of flow-limiting control measures and bottlenecks is used. Whether a certain set of control measures is sufficient to improve network performance is determined. The approach also supplies the necessary sequence of control actions and the necessary relocation of traffic jams to achieve the network state corresponding to the best achievable performance.
Abstract