Development and Evaluation of Lane-By-Lane Gap-Out Based Actuated Traffic Signal Control

Final report.PDFTech ReportUVA-2008-02DTRT07-G-0003Traffic characteristicsGap acceptanceActuated traffic signal controllersTraffic signal controllersTraffic signal hardwareTraffic control devicesHighway traffic controlTraffic controlSimulationOptimizationVirginiaMid-Atlantic Universities Transportation CenterLee, JoyoungStrack, EricPark, ByungkyuUniversity of Virginia. Center for Transportation StudiesVirginia Transportation Research CouncilVirginia. Dept. of TransportationUnited States. Dept. of Transportation. Research and Innovative Technology AdministrationUnited States. Federal Highway AdministrationNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control DevicesNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic FlowUS Transportation CollectionActuated traffic signal controls at isolated intersections largely benefit from gap-out and phase skip features as they allowunused green times to be re-allocated to those movements need them. A few studies indicated that lane-by-lane gap-outshould be implemented for multi-lane approaches instead of traditional combined single channel gap-out. While the lane-bylanegap-out is logically better than the combined channel gap-out, no studies have shown the delay benefits under theoptimized green splits and gap-out times.This research developed a lane-by-lane gap-out-based actuated signal control optimization method and evaluated itsperformance using four demand cases covering volume-to-capacity ratios between 0.4 and 1.3. A simulation-based studyindicated that the lane-by-lane gap-out outperformed the combined single channel gap-out for all these cases. It was foundthat over 12% total delay savings were observed for high volume-to-capacity ratio cases