In Spring 2010, the Illinois Department of Transportation initiated an area-wide implementation to integrate the flashing yellow arrow as the display for the left-turn permissive interval at more than 100 intersections operating with protected/permissive left-turn (PPLT) control. Bradley University was retained to perform an effectiveness evaluation of the FYA at these locations. The purpose of this research was to evaluate the effect on safety and operations of upgrading the circular green permissive indication to FYA indications at intersections operating with PPLT phasing. The research tasks included performing comprehensive, area-wide traffic crash analyses; conducting field studies of traffic operations and traffic conflicts; and assessing driver comprehension of the new traffic control through a survey instrument. To fulfil the research objectives, a comprehensive state-of-the-art literature review was conducted; the findings are documented in this report. The purpose of the literature review was to document the current knowledge and research findings involving PPLT control, and specifically, studies involving FYA indications. More than 30 journal papers, reports and other published documents were reviewed. These sources reported findings from driver comprehension studies, driving simulator studies, crash-based evaluations, and operational effects of various PPLT control strategies, including the flashing yellow arrow. This report provides a synthesis of the state-of-the-art on various left-turn traffic control strategies. (Author/publisher)
Samenvatting