New York State Department of Transportation Engineering Services in Conjunction with Suffolk County Traffic Signal Retiming

A primary objective of this project is to create optimum traffic flow patterns, thereby reducing vehicle delay, vehicle stops, fuel consumption, and vehicle emissions. This goal is being achieved with the development of innovative timing plans through the use of a Synchro traffic signal optimization program. GPI will meet these objectives through a carefully structured plan. GPI’s thorough understanding of the project was realized by its local knowledge of the County roadway network, past experience on similar projects, and extensive understanding of timing plan development.

Project deliverables will include turning movement volume counts, time-space diagrams, traffic signal coordinated timing plans, project summary reports with MOE’s, and Synchro data files for the project intersections. This information is being developed to be incorporated into a database management program to assist the County in the maintenance and operation of signals countywide.

The GPI team collected data and assembled current intersection plans and timing data from the State, developed an inventory of traffic signal equipment and capabilities, and collected additional traffic volume data. A traffic analysis was conducted of existing conditions to develop a current database for signal timing simulation and optimization signal timing plans and time-space diagrams utilizing Synchro, and/or SIMTraffic. A signal system report documented the traffic analysis and optimizations for NYSDOT review and comment.

The team investigated, studied, analyzed, and documented traffic signal timing requests, investigated alternatives and recommended actions. Under NYSDOT supervision, proposed timings in traffic signal controllers and fine-tuned timing plans were implemented in the field to further reflect ambient traffic conditions and measure improvements resulting from the optimized timing. Electronic records documented optimized arterial coordination and traffic signal timing using NYSDOT and Synchro formats for all roadway segments.