Twin Ports Interchange

The $435 million Twin Ports Interchange project reconstructs the system-to-system interchange of I-535 and US 53 with I-35 in Duluth, Minnesota. In total, the interchange experiences an average of 80,000 vehicles each day, of which 5,320 are classified as heavy commercial. Key project elements include interchange reconfiguration and geometric safety improvements, stormwater treatment and system improvements, geotechnical soil stabilization and load transfer platforms, utility relocations and improvements, creek realignments, and local roadway upgrades.

This project is a massive multi-phase effort that will untangle the current system by incorporating safety improvements while replacing aging infrastructure on this northernmost point of I-35. A significant goal of the project is to improve the movement of freight and goods between the ports of Duluth, Minnesota and Superior, Wisconsin and the upper Midwest.

Alliant’s multi-year involvement began in 2016 with a preliminary engineering design effort, where Alliant served as Project Manager and Roadway Design Lead. Services included alternatives evaluation and associated stakeholder engagement, conceptual interchange design, traffic forecasting, and freeway modeling, Interstate Access Modification Request, grant funding application assistance, and preliminary cost estimating. Several local road connections and supporting infrastructure improvements were also identified, evaluated, and incorporated into the final design layout. Alliant’s final design scope of work includes fulfilling the Roadway Design Manager for the project, final design of the main interchange and Interstate work, Maintenance of Traffic, and Intelligent Transportation System design.

Images provided by Minnesota Department of Transportation.