Dynamic flashing yellow arrow (FYA): a study on variable left-turn mode operational and safety impacts phase II - model expansion and testing.

PDFTech ReportBDV24-977-10Signalized intersectionsLeft turn phaseFlashing traffic signalsArrows (Signals)Yellow interval (Traffic signal cycle)Decision support systemsTraffic control centersTraffic safetyExclusive permissive phasingPeriods of the dayFloridaUnited StatesFlorida. Dept. of TransportationAbou-Senna, HatemRadwan, EssamEldeeb, HeshamNavarro, AlexUniversity of Central Florida. Center for Advanced Transportation Systems SimulationFlorida. Dept. of Transportation. Research CenterUS Transportation CollectionThe flashing yellow arrow (FYA) signal display creates an opportunity to enhance the left-turn phase with avariable mode that can be changed on demand. The previously developed decision support system (DSS) inphase I facilitated the selection of the FYA left-turn mode, changing by time of day at intersections. There was aneed to continue to refine the interactive framework to improve its service. However, the ultimate objective ofthe continued research of phase II was to demonstrate the ability to execute the automation of the process. PhaseII of the FYA project provided additional intersection data that refined the work that was previously completed.Virtual testing of the DSS was first conducted using VISSIM application programming interface (API) to confirmthe validity of the procedure and logic. The DSS was then tested in a field testing environment. A customcommunications software was developed to retrieve instantaneous channel input data, synchronize opposing thrugreen phase, analyze traffic information, provide the algorithm decision, and generate a real-time log recordingthe events. The proposed algorithm is implemented with the goal of safely optimizing traffic operations withconstant analysis in real-time to determine whether it would be optimal to switch the red arrow to a flashingyellow arrow. The algorithm determines the time interval between the successive arrivals of vehicles andcomputes the corresponding headway for each lane by cycle on a second-by-second basis. The DSS wasultimately tested at two different intersections in Seminole County. The DSS testing confirmed the applicabilityand validity of the developed DSS as well as the aforementioned procedure, criteria, and logic