The Road Commission for Oakland County selected Hubbell, Roth & Clark, Inc. and its subconsultants, Parsons Brinkerhoff and Orchard Hiltz & McCliment, to analyze and retime 320 traffic signals in 13 communities in southeast Oakland County. The project is funded by MDOT with a federal grant from the Congestion Mitigation Air Quality Program. The goal of the program is to improve the efficiency and safety of the roadway network and over the long term to improve air quality by optimizing the signal timings and providing progressive traffic movement on the major corridors. GIS staff assisted in this project by mapping the affected intersections throughout the County. The GIS staff also developed a linkage between the Synchro (modeling and optimizing traffic signal timing software) and ArcGIS, which allows the display of lane-by-lane counts by approach in a standard GIS format.

HRC responsibilities included:

• Collect detailed traffic count data, geometric data and photographs of every approach.
• Provide a detailed network signal progression plan with optimized traffic signal operations for at least three periods for over 300 intersections.
• Provide timing charts required by the agencies with traffic signal maintenance responsibilities, namely RCOC, Pontiac, Royal Oak and Ferndale.
• Conduct a follow-up critique of the network and recommend adjustments to the system as required.
• Provide a smoother commute with better synchronization of red lights.
• Provide a traffic simulation of the system-wide signal system by integrating with County GIS data.

Data including volume by lane and intersection geometry was transferred from a traffic signal timing optimization software package (Synchro) into ArcGIS and mapped. Problem intersections are easily identified on maps showing intersection volume.