STV designed a state-of-the-art five-span bridge for the Illinois Department of Transportation, replacing an old, outdated interchange.
The new IL 162 over I-55/70 interchange is the largest American Recovery Reinvestment Act funded transportation project in the state. The project features a unique, single-point diamond interchange design, which handles traffic safely and efficiently. It is one of only four such interchanges in the state. This design reduces the number of traffic signals and allows for more gradual turns for large vehicles. Numerous studies were conducted to implement complex drainage systems at the site. Two mechanically stabilized earth retaining walls were constructed at the site to mitigate weak soil conditions.