City of Phoenix, AZ; Arizona DOT and the Maricopa Council of Governments
Traffic Management is constantly changing, and finding resolutions to this challenging process requires “out-of-the-box” thinking. Lee Engineering worked with Maricopa 
Association of Governments (MAG), ADOT, and the City of Phoenix to complete Phase 1 of the I-10 Freeway Diversion route management study. This effort was developed to route traffic away from extended closures of the I-10 Freeway due to collisions or other incidents, onto City of Phoenix surface streets, and developing signal timing plans and diversion route strategies to handle the added volumes. Together, and in parallel paths, Lee Engineering and the local Metropolitan Planning Organization developed baseline models in Synchro, and in the MAG DynusT traffic simulation and assignment software. The DynusT model volumes were then loaded into Synchro for four different closures scenarios, in two different directions, during the morning and evening peak hours. Several different cycle lengths and splits were analyzed to find the least amount of delay for each scenario, while attempting to move the most amount of traffic though several specific diversionary routes.
The next phase of the project will transfer the timing plans in to the Phoenix traffic signal system to be implemented during those events that close portions of the freeway. This coordinated implementation of changing timing plans will be done at different times during the closure while supporting field devices are installed, thus creating dual left turn movements where only one existed normally.