ADHDP(λ) strategies based coordinated ramps metering with queuing consideration

Ramp metering has been developed as a traffic management strategy to alleviate congestion on freeways. Most ramp metering control algorithms are concerned without queuing consideration, because its still a tough job to deal with the problems of coordinated multiple ramps metering with queuing consideration. In this paper, on the basis of our previous studies, we use action-dependent heuristic dynamic programming based on eligibility traces (ADHDP(lambda)) to solve local ramp metering and multiple ramps metering problems with queuing consideration. First, for the local ramp metering problem, we establish a comprehensive performance index which considers both traffic density and on-ramp queue length. Second, for the multiple ramps metering problem, based on ADHDP(lambda), the coordinated ramps metering and regulating queue lengths are achieved at the same time. Simulation studies on a hypothetical freeway are reported. It is shown that the proposed control scheme is efficient.