Transportation Research Record Journal of the Transportation Research Board · 1991 · 77 citations · 2 references
EngineeringIndustrial EngineeringSystems EngineeringOptimizationReal-time SystemsSchedulingAdaptive ControlIntelligent Transportation SystemsReal-time ControlTraffic EngineeringTraffic OperationsTraffic Signal ControlDemand-responsive TransportationIncremental CostsReal-time ProcessingReal-time Traffic ControlSignal TimingSignal Timing OptimizationTraffic Signal OptimizationTraffic Signal Timing
Optimization Policies for Adaptive Control (OPAC) is an on-line control algorithm designed to optimize the performance of individual traffic signals. It is a building block for demand-responsive control of a distributed signal system. OPAC-RT is a traffic signal control system that implements the OPAC strategy in real time. The system uses traffic data collected from detectors located well upstream (400 to 600 ft) of the stop bar on all approaches to an intersection. Signal timings are dynamically optimized in a demand-responsive manner using a rolling horizon scheme. Results of the first implementation and field testing of the on-line OPAC strategy at individual intersections indicate that OPAC performs better than well-timed actuated signals, particularly at greater demand levels. The payback period of the incremental costs of installing the current version of OPAC is estimated to be less than 1 year. Further enhancements of the OPAC system operation are likely to significantly increase its effectiveness.
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