I-39 & US-20 Interchange

Illinois Department of Transportation | Winnebago County, IL
Rendering of a new diverging diamond interchange carrying US-20 over I-39

IDOT planned to reconstruct and widen I-39 from US-20 to north of Harrison Avenue. The project aimed to widen the interstate from four lanes with a grassed median to six lanes with a paved median separated by a median barrier, as well as an auxiliary lane in each direction.

As a part of our design contract with for the I-39/US 29 improvements in Rock Island, Benesch provided an independent Value Engineering analysis of the project with team members from the Illinois DOT, Benesch and other subconsultants. The scope of work included the study of a proposed Diverging Diamond Interchange at I-39 and Harrison Avenue, the reconstruction and widening of I-39, geometric improvements to the I-39/US-20 Interchange and replacement of 14 bridges including twin bridges over the Kishwaukee River.

During the analysis, alternatives for each of these elements were evaluated for value and functionality. The VE team speculated on 135 ideas for the project and developed eight concepts with a Maximum Potential Construction Cost Avoidance of $579,000. Benesch led a blended VE team consisting of Benesch design team members and IDOT staff. Considerations for traffic management upgrades, noise control and environmental complications at river bridge locations were included in the study.