Illinois Tollway’s Cherry Valley interchange
The Illinois Tollway selected Hanson to provide preliminary engineering, project design and construction design-support services for the reconfiguration and reconstruction of the Cherry Valley Interchange – the Illinois Tollway’s Jane Addams Memorial Tollway (Interstate 90) and Interstate 39 interchange.
The previous interchange had a trumpet-type design with a tight loop ramp connecting northbound I-39 with westbound I-90. The tight geometry did not adequately handle the operating speeds appropriate for a system interchange, and the corridor had experienced significant traffic growth, leading to increased congestion.
Hanson studied 10 different improvement alternatives. The final improvement featured a fly-over ramp bridge and required little right-of-way acquisition and no property-owner displacements. The new and improved Cherry Valley interchange provides for higher operating speeds, increased capacity and reduced congestion.
The interchange improvement included reconstruction of two miles of I-90, 0.5 miles of I-39, four ramps, three bridges, five retaining walls, a portion of U.S. 20/Irene Road intersection, and a new exit ramp from I-90 to Irene Road.
Hanson’s Phase I services included the preparation of pre-concept, master plan and drainage concept reports; a traffic study; and an environmental evaluation document. The project team also completed a micro-simulation model in VISSIM that helped justify the preferred alternative.
Phase II services were performed in an expedited schedule to allow the Illinois Tollway to procure the work in the fall and take advantage of a more competitive construction marketplace. Final plans were delivered ahead of schedule.
As part of the Phase II services necessary for the construction documents, Hanson provided:
- structural design for the Newburg Road Bridge,
- 30 percent design of two new bridges and retaining walls (which were delivered as performance specifications),
- Maintenance-of-traffic plan development,
- roadway design,
- drainage design,
- permanent erosion control and seeding,
- utility coordination including fiber optics,
- traffic engineering,
- barrier warrant analyses for the placement of guardrails, concrete barriers and cable guard rails,
- final noise analysis,
- right-of-way plats preparation, and
- geotechnical engineering services.
Hanson worked with four subconsultants and used ProjectWise, a document management system, to streamline file management.
In Phase III, Hanson provided design-support services to the construction manager. Hanson was a part of a construction team that enjoyed a cooperative working relationship, which resulted in a needed improvement and a satisfied customer.