SPR 18-565 Traffic Signal Strategies for Oversaturated Conditions

With ever-increasing traffic volumes, congestion continues to grow significantly in Kentucky especially in our major population centers. On many arterials, traffic demand exceeds capacity restricting the mobility. Standard signal timing practices which seek to maximize greenbands through an arterial system, may not operate as well during oversaturated conditions, due to queue spillback and blockages which can prohibit vehicles from arriving at downstream signals during the greenband. Several methods to address oversaturated signal timing methods have been proposed and used by others including gating, offset weighting, and reverse progression etc. Recent signal timing plan strategies deployed in Kentucky have demonstrated up to 85 percent reductions in travel time during peak hours. While these methods show promise they also typically require extensive data collection and analysis. There exists a need for an efficient methodology that will allow engineers to identify and diagnose oversaturated conditions and implement readily available counte1measures using current signal timing practices and available data. The recent acquisition of W aze travel time data for Kentucky roadways provides an opportunity to leverage new technologies to address these challenges in operating oversaturated traffic signal systems. *** This Research Program for the period July 1, 2016 to June 30, 2018 is submitted in compliance with the provisions of Section 307 of Title 23, United States Code, and describes programs and operations for planning activities in the Kentucky Transportation Cabinet (KYTC) and the Kentucky Cooperative Transportation Research Program (KCTRP). This program modifies and updates such programs and is specifically intended to reflect the needs of the Kentucky Transportation Cabinet. It is fully expected that products from this program will also have national applications. The University of Kentucky Transportation Center is the main research group for the the Kentucky Transportation Cabinet. The SPR grant is the funding the is supplied each year for the many topics the Center is asked to research for KYTC The KCTRP is concerned with the development and conduct of a comprehensive research program in cooperation with the U.S. Department of Transportation, Federal Highway Administration (FHWA). In addition to research developed in cooperation with FHWA, the KCTRP may perform other services for the KYTC on a nonparticipating basis. The scope of these services could include activities such as research studies and special investigations of various engineering and operation activities. The Research Program and Implementation Advisory Committee (RPIAC), headed by the State Highway Engineer and coordinated through the Research Coordinator, will give direction to the research program.