Adaptive signal control has the potential to provide improved control at isolated intersections. Adaptive control, however, has limitations due to its need to rely on estimated flow conditions for making signal timing decisions. Such estimated flow conditions always differ from the actual conditions, and the discrepancies can offset the benefit of having an elaborate decision making process in a control logic. Therefore, an issue can be raised as to whether it is necessary to rely on strenuous decision-making processes for adaptive control. This study compares the relative merits of a simple queue based logic and a logic that relies on a much more complicated procedure for making timing decisions. It is found that the queue-based logic is nearly as effective as the more complicated logic. This finding points to a direction for the development of new control logics that can be widely used to replace existing traffic-actuated control logics.
Abstract