Agenda - Economic Development Authority - 10/09/2014

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EVALUATION OF CONCEPTS EVALUATION OF CONCEPTS Project Grouping Analysis In order to better understand safety and mobility benefits gained through the conceptualized improvement projects, groups of projects were analyzed corridor -wide. The analysis was based on the anticipated sequencing of projects due to construction feasibility, access, and general support. The overall approach taken was to construct all of the Approach 1 access management projects prior to grade separating any intersections. Fol- lowing access management, it was assumed construction would start on the east end of the corridor by grade separating westbound traffic and heading to the west. Eastbound grade separation followed in a similar manner. This strategy also assumed that Ramsey Blvd. and Sunfish Lake Blvd. were related. The alternative chosen at one would impact what was built at the other. For that reason, some of the project groups show improvements being made at both locations simultaneously. Corridor Simulation Process The project group analysis was completed using VISSIM. Approach 1 projects were built in the model on top of the base model used to develop existing conditions with each subsequent project group building on the last. The geometry was not modeled to exactly match the concept drawings as this analysis was meant to be high level. Similarly, the different concepts are interchangeable at a particular intersection in terms of the operations and safety analysis since the overall goal of grade separating mainline traffic is achieved in any alternative. Evaluation Criteria The project groups were evaluated based on existing traffic conditions modeled after project group completion. The safety metric chosen was total number of crashes at each primary intersection and the segments in-be- tween. Crash modification factors' were used to reduce the number of crashes at each location based on the type of improvement proposed in a project group. Total hours of vehicle delay' at each primary intersection was used to gauge mobility benefits. The delay values were gathered from the VISSIM model of each project group and show how improving one location can have negative effects on locations downstream. Project Groupings Project Group 1— Access Management All access management/Approach 1 projects are assumed to be constructed in this grouping. The Armstrong interchange is taken to be built prior to this construction occurring. 7 Crash Modification Factor — Values given, typically from the AASHTO Highway Safety Manual, which represent the percentage of a type of crash remaining after an improvement is made. 8 Total Vehicle Hours of Delay — Sum of delay each vehicle encounters when navigating through an intersection quantified as hours. HIGHWAY 10 ACCESS PLANNING STUDY 60