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The flashing yellow arrow (FYA) signal display creates an opportunity to enhance the left-turn phase with a variable mode that can be changed on demand. This paper presents phase II of the research. Phase I developed a decision support system (DSS) to select the FYA left-turn mode, and changing by time of day at intersections. There was a need to continue to refine the interactive framework to improve its service. However, the ultimate objective of the continued research of phase II was to demonstrate the ability to execute the automation of the process. Phase II of the FYA project provided additional intersection data that refined the model. Virtual testing of the DSS was first conducted using VISSIM application programming interface (API) before the field testing environment. A Custom communications software was developed to retrieve instantaneous channel input data, synchronize opposing thru green phase, analyze traffic information, provide the algorithm decision, and generate a real-time log recording the events to determine whether it would be optimal to switch the red arrow to a flashing yellow arrow. The algorithm determines the time interval between the successive arrivals of vehicles and computes the corresponding headway for each lane by cycle on a second-by-second basis. The DSS was ultimately tested at two different intersections in Seminole County. The FYA 4-section configuration provides the opportunity for a fully adjustable system and provides the TMCs with more tools to operate the intersections as efficiently as possible at peak and off-peak times. |
