Airport Road & IL Route 126 Stevenson Expressway (I-55) Interchange Phase I

The six-mile stretch of the Stevenson Expressway (I-55) between US Route 30 and Weber Road currently has only one interchange, consisting of a northbound on-ramp and a southbound off-ramp at IL Route 126. In accordance with NEPA requirements, our team provided Phase I engineering services for two full-access interchanges in Will County, IL. Our services included traffic projections, traffic modeling, geometric studies, interchange and intersection design studies, access justification report, environmental assessment, combined design report, traffic management analysis, bridge condition evaluations, and location drainage study. The preferred build alternative includes a new full access interchange at Airport Road and a reconfigured interchange at IL 126, providing full access.

Additional Info

Project Highlights:

Key challenges included modifying an existing partial interchange to provide full access in both directions, in a corridor surrounded by wetlands.
Study limits included 3.5 miles of I-55, one mile of Airport / Lockport Road, one mile of IL Route 126, a half mile of Essington Road, and a half mile of 135th Street.
The corridor also included Section 4(f) properties as well as other sensitive environmental issues involving noise, water quality, flooding, wetlands, special waste, and traffic impacts which were documented in an environmental assessment.
We also conducted bridge condition evaluations for three structures: two that cross the expressway and one that traverses Lily Cache Creek, for which we also performed a hydraulic analysis to design the waterway opening for the creek under Lockport Road.
Phase I engineering services also included the preparation of a combined design report, interchange type study, updated access justification report and location drainage study.
The project also featured an extensive public involvement program which follows the principles of IDOT Context Sensitive Solutions procedures. To date, this program has included a stakeholder involvement plan, community context audit report, three public meetings, six community advisory group meetings, a project website and local government official briefings.