The Kishwaukee River Bridges are twin prestressed concrete box girder structures, located in Winnebago County, Illinois. The bridges are part of the Supplemental Federal Aid Freeway, FA412, which is being built to Interstate standards and financed jointly by the Federal Highway Administration and the State of Illinois. This Supplemental Freeway will become the main North-South highway serving the mid-section of Illinois. The site of the Kishwaukee River Bridges is about 4 miles (6'/2 km) south of Rockford. The box girders were constructed from precast segments which were erected by means of a launching truss. This project represented the first use of a launching truss for segmental bridge erection in the United States. Another significant feature of the project is that contractors were given an unusually high (for 1976) degree of freedom to choose their own construction methods and details.
