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  • Location: Clark County, Ohio

The Clark County Transportation Coordinating Committee, in collaboration with Clark County, the City of Springfield and ODOT District 7, identified the need to create a list of prioritized locations for future single-lane roundabouts across the county. The study focused on addressing crashes, improving capacity and considering all users in the improvements.

B&N was selected to develop a skim analysis process to assess intersections and develop a list of prioritized intersections. Our team developed a public engagement site with an interactive GIS map and project survey that recorded over 400 responses from county residents and supported the skim analysis results. After selecting a top 50 list of intersections, the team prepared preliminary layouts and cost estimates for the top 10 intersections for the stakeholders to use for funding efforts.

With thousands of intersections across the county, identifying a strategy to assess and prioritize the intersections quickly was critical to the project. Clark County currently has two constructed roundabouts, with a few more planned. These innovative intersections are new to the Clark County residents, and this intersection type's reception was not well known. With numerous urban and rural locations and the likelihood that more urban locations could rank higher than rural locations, the need to balance recommended improvement locations was necessary to create a well-rounded plan.

B&N efficiently analyzed the intersections using a statistical skim analysis methodology developed in other recent projects. The team also used an online interactive hub site to capture public feedback. Based on feedback from the stakeholders, the single prioritized list was broken down into three lists: Springfield, other urban locations and rural locations. This provided a balanced approach to selecting intersections for further study across all contexts.

The team evaluated over 1,000 intersections for potential roundabout implementation. We integrated over a dozen disparate indicators into a unified analysis framework, combining network characteristics and community sentiment to ensure comprehensive decision-making. The team also participated in a structured focus group to assess each indicator's importance in determining suitability for roundabout implementation. The team used GIS to collect and overlay the data for each intersection. Additionally, with over 200 survey entries, the team used machine learning and sentiment analysis to get a broad understanding of conditions on the ground from community members.

This skim analysis is unique because it allowed the team to analyze over 1,000 intersections quickly and efficiently. Given that we were incorporating transportation data, community input, and subject matter expertise to ensure the best outcomes, this task would have been impossible without a strong foundation in GIS and statistical analysis.

B&N will use the top 10 list developed from this analysis to provide the stakeholders with projects that improve safety and capacity and have a high potential for funding and construction. The locations of some of the roundabouts are adjacent to schools and will provide traffic calming to those intersections. The community will see improved safety and access at these locations. With the community unfamiliar with roundabouts, the selected locations are straightforward, single-lane roundabouts, perfect for introducing “first” roundabouts for those learning to navigate the intersection.