Abstract Manager

Transportation professionals rarely have the luxury of designing an intersection or interchange with no constraints or complexities. They must use every tool in their toolbox to find an optimal solution and strike a balance between all stakeholders, agency desires, and practical limitations.

This presentation will highlight a signalized turbine interchange in the western suburbs of Chicago, Illinois. This interchange features complex and innovative solutions to maintain local connections and access. The initial study recommended a diverging diamond interchange (DDI) or adding lanes to the arterial corridor and making the needed adjustments to the interchange ramp terminals while maintaining the existing concept. Neither of these options solved some of the complex issues facing this area caused primarily by a fifth leg, an arterial that starts from this interchange and connects directly to downtown Elgin. 

While the signalized turbine became the preferred technical concept, funding became a critical concern that forced a rethinking of construction staging and a pivot toward an incremental implementation strategy to fit into available funding. The focus turned to developing a plan to build the project in stages where interim configurations must deliver substantial operational improvements while potentially remaining in place for years.

The project location is constrained by residential and commercial development as well as environmentally sensitive lands leading to the development of this compact improvement concept.  This presentation will highlight design elements and considerations of this unique interchange type that should be considered when comparing alternatives and will discuss the additional unique interchange types that were created to facilitate its implementation.