Challenge
The Illinois Department of Transportation (IDOT) District 1 needed to reconstruct and expand a heavily traveled section of I-55 from I-80 to US 52, including a complete reconstruction of the I-55/IL-59 interchange. The project included added interstate capacity between IL-59 and US 52, new ramps, roadway and intersection improvements, and extensive structural, drainage, lighting, traffic signals, multimodal, and landscaping enhancements. As the primary gateway to the 310-acre Rock Run Collection development, maintaining reliable access was critical to supporting economic growth in Joliet, Shorewood, and the surrounding region.
Schedule was the project’s greatest challenge. Construction began nearly eight months late because preceding IDOT projects had to be completed first, reducing the available construction window from three seasons to just over two. Despite the delay, IDOT maintained the original interchange opening date due to commitments tied to the development.
Construction complexity added further pressure, requiring coordination with adjacent local and IDOT construction projects, major infrastructure improvements, utility coordination, and extensive traffic staging while maintaining interstate traffic, local access, and emergency response through a highly visible work zone.
Solution
HR Green provided Phase III engineering and construction management services, serving as IDOT’s representative in the field and coordinating closely with contractors, utilities, public agencies, and multiple IDOT departments.
The team strategically sequenced work, modified maintenance-of-traffic staging as needed throughout the project, and closely monitored schedules, submittals, and reviews to identify and address potential delays before they affected key milestones.
A centerpiece of the project was converting the I-55/IL-59 interchange into a diverging diamond interchange, improving traffic operations and safety. Additional improvements included widening I-55 and IL-59, constructing new ramps, upgrading traffic signals and lighting, expanding ITS infrastructure, and replacing approximately 18,500 feet of fiber-optic cable.
HR Green also led contract administration, inspection, documentation, quality assurance, and quantity verification. Early quantity reviews identified discrepancies in retaining wall and noise wall designs, allowing corrective action before construction impacts occurred. The team also worked with IDOT soils personnel to develop targeted remediation plans for unsuitable and non-special waste materials, reducing unnecessary excavation, hauling, and replacement costs for the Deparment.
Despite the delayed start, the interchange opened on the original target date and reached substantial completion about a week ahead of schedule. Three separate IDOT audits found zero documentation deficiencies, reflecting strong project controls and record management throughout construction. Additionally, the project was completed approximately 7% below the as-bid budget.
Benefit
The completed interchange has improved mobility, safety, and connectivity throughout the corridor. Increased capacity and the diverging diamond design have reduced congestion, improved traffic flow, enhanced regional access, and lowered the potential for severe crashes.
A new shared-use path now connects Joliet and Shorewood across I-55, creating safer and more accessible connections for pedestrians and cyclists traveling to destinations such as Rock Run Collection and Joliet Junior College.
The project also benefits nearby neighborhoods through noise reduction with the addition of noise abatement walls along I-55, environmental restoration through expanded natural prairie grass and wetland areas, landscaping enhancements, and improved stormwater management. Beyond transportation improvements, the interchange has become a catalyst for investment in a historically underutilized area of Will County. Since completion, significant commercial and residential development has advanced in the surrounding area, including a casino and additional hospitality, retail, and housing projects that continue to strengthen the regional economy.
