Client: Illinois Tollway

Clark Dietz provided construction engineering services for the replacement of the structure carrying the flyover from I-55 to northbound I-294 (Ramp A) over the Tri-State Tollway, as well as the reconstruction of the exit ramp from northbound I-294 to the Hinsdale Oasis (Ramp N).

Project Overview:

Location: This work was done under Contract I-19-4491 along the Tri-State (I-294) Tollway, specifically between Mile Post 24.0 and Mile Post 24.5 in Cook County.

This image shows a newly constructed highway lane at night, likely near completion.

Scope of Work:

The project involved the replacement of the structure carrying the flyover from I-55 to northbound I-294 (Ramp A) over the Tri-State Tollway (BN 247). Additionally, the exit ramp from northbound I-294 to the Hinsdale Oasis (Ramp N) was fully reconstructed.

Storm and sanitary sewers were constructed, along with necessary drainage improvements to support long-term functionality. Both permanent and temporary erosion control measures were implemented to stabilize the work area during and after construction.

Wall construction included the installation of moment slabs, noise walls, retaining walls, and mechanically stabilized earth (MSE) walls. Shoring and structural work required the review and implementation of a design for temporary shoring towers to support key elements of the project.

Traffic control improvements included the installation of pavement markings, guardrails, concrete barriers, and both permanent and temporary lighting to ensure motorist safety. Skewed 92-inch curved steel girders were installed, and the existing structure was demolished.

Other work included the use of lightweight fill and oversight of performance specifications for both noise abatement walls and temporary soil retention systems.

This image captures a bridge deck concrete pouring operation in progress during daytime.

Project Coordination:

  • Mainline Coordination: Extensive coordination with mainline contracts was required, as the mainline reconstruction was happening at the same time.

  • Phase III Engineering Services: Clark Dietz provided inspection and supervision for selected locations throughout various projects related to the Central Tri-State Tollway.

Recognition:

“Flagg Creek Water Reclamation District was pleased to have worked with Clark Dietz on this major sewer relocation work required by the Illinois Tollway for the I-294 Expansion Project.  This work required a high degree of partnering between design, construction and operations, and Clark Dietz’s construction engineering team was always helpful, competent and professional, making this project a success,” says James Liubicich, P.E., Executive Director of Flagg Creek Water Reclamation District.

Work Orders and Compensation:

Work orders under the blanket agreement are negotiated and authorized by the Tollway as needed, with an upper compensation limit of $7.5 million to be used as individual projects are required.