I-39/90 & I-43/WIS 81 Interchange
2025 Engineering Excellence Best of State
Entering Firm: AECOM
Client: Wisconsin Department of Transportation
Designing the Right Interchange
The I-39/90 and I-43/WIS 81 interchange in Beloit underwent transformative upgrades to improve safety, meet modern design standards, accommodate future traffic demands and enhance local mobility. Situated in one of Wisconsin’s busiest traffic and freight corridors, the project required careful staging and innovative solutions to navigate its complexities.
AECOM led the transformation with innovative engineering solutions, delivering a landmark project that supports the region’s economic and transportation needs. A key innovation was embedding a local service interchange for WIS 81 within the free-flow I-39/90 & I-43 interchange, achieving seamless integration of regional and local traffic. The design strategically placed new roadways to accelerate construction while minimizing traffic disruptions and land use impacts. Advanced engineering techniques were used for the expansive curved steel girder bridges, including pile testing to optimize foundations, high-performance steel and wind-resilient construction methods, reducing costs and ensuring durability.
Innovative Engineering Design in Action
Construction featured a unique staging technique, temporarily reconfiguring traffic patterns to improve safety and shorten the construction timeline. Extensive stakeholder engagement allowed decision-makers to understand complex design factors, streamlining approvals and expediting project delivery.
Awards judge Brandon Braithwaite said, “The I39/90 & I43/WIS 81 interchange project is undoubtedly award-worthy considering the project's sheer complexity, innovative solutions, and immense coordination during design and construction. Kudos to all involved and congratulations on showcasing our great state to all who enter Wisconsin from this southern corridor.”
A Modern Interchange
AECOM delivered a project that balances budget considerations with technical innovation. The interchange not only meets today’s transportation needs but also fosters economic growth and sets a new standard for sustainable infrastructure in Wisconsin. This project exemplifies the power of collaboration and cutting-edge engineering in redefining regional connectivity.