Evaluating Ramp Meter Wait Time in Utah

2022PDFTech ReportSchultz, Grant G.Macfarlane, Gregory SDaines, Tanner JWard, Cory KUmphress, JamesBrigham Young University. Department of Civil and Environmental EngineeringUtah Department of TransportationUnited States. Department of Transportation. Federal Highway AdministrationUtah Department of TransportationUnited StatesUtahRamp meteringLengthQueuingDelaysTypes of detectorsKalman filteringUT- 22.0620-8679Final reportThe purpose of this project is to develop an algorithm that can predict ramp meter wait time at metered freeway on-ramps throughout the state of Utah using existing loop detector systems on the ramps. The loop detectors provide data in 60-second increments that include volume, occupancy, and the metering rate. Using these data sources, several ramp meter queue length algorithms were applied; these predicted queue lengths can then be converted into wait times by using the metering rate provided by the detector data. A conservation model and several variations of a Kalman filter model generated predicted queue lengths and wait times that were compared to the observed queue lengths. The Vigos model\u2014the model that yielded the best results\u2014provided wait time estimates that were generally within approximately 45 seconds of the observed wait time. This model is simple to implement and can be automated for UDOT to provide wait time estimates at any metered on-ramp throughout the state.131