TYLin provided Phase I Environmental Assessment and Phase II Engineering Services for the construction of the I-57 Interchange at I-294 (Tri-State Tollway) in Cook County, Illinois.
Completed for the Illinois Department of Transportation (IDOT), the I-57 at I-294 Interchange Project connected these important highways, reducing travel times and congestion on local routes.
Project elements analyzed in Phase I included the geometry of multiple new ramps and flyover bridges at the I-57/I-294 Interchange, bridge replacements at the I-57/147th Street and I-294/147th Street Interchanges, and bridge inspections and condition reports for modifications to accommodate new or revised geometrics. Other elements included multiple retaining walls, and extensions and/or replacements of existing box culverts and new box culverts.
After investigating the project area and conducting studies, TYLin made recommendations in a Combined Design Report, with Structure Type, Size and Location drawings for 19 structures.
Phase II included providing the Project Management Plan, the Project Financial Plan, and project scheduling for plan production bidding and construction. Along with main contracts for roadways, ramps, and bridges, small business contracts were also prepared for the demolition of 32 buildings, utilities relocation, off-system roadway pavement work, and aesthetic landscaping.
TYLin also performed analysis for the construction of a new, adjacent partial diamond interchange where I-294 crosses over 147th Street (IL 83). Improvements to the existing I-57/147th Street diamond-type interchange and potential capacity issues, roadway deficiencies, and safety needs along 147th Street were addressed.
- Extensive coordination was required with IDOT, the Illinois State Toll Highway Authority, adjacent suburban communities, other related permitting agencies, and subconsultants.
- The Environmental Assessment was processed on an accelerated schedule, with design approval received one year after notice-to-proceed.
- Along with a Constructability Review, TYLin evaluated the interchange design according to the I-LAST™ Illinois-Livable and Sustainable Transportation (I-LAST) Rating System and Guide.
- A Crash Analysis Report and overall project Maintenance of Traffic planning and scheduling were provided.
- Conceptual signage, pavement marking types, traffic signals, lighting concepts, and the inclusion of an all-electronic toll collection system were part of TYLin’s assessment.
- A total of 15 separate sets of construction bid packages were prepared, including plans, specifications, schedules, and cost estimates.
- TYLin also provided the Drainage Study for the relocation of Dixie Creek, compensatory storage, detention pond analysis and locations, and floodway impacts.
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