In 2015, the Illinois Tollway initiated a master planning effort to study necessary improvements to a 22-mile section of Interstate 294, the Central Tri-State Tollway, extending from the 95th Street interchange in Hickory Hills and Bridgeview to Balmoral Avenue near O’Hare International Airport. Hanson served as the design corridor manager, overseeing four design teams in developing a planning document to guide the Tollway’s reconstruction program.
Traffic modeling indicated the highest design-year traffic volumes would occur in the critical section between the I-55 and I-88 interchanges. The preferred alternative widened this section from eight lanes to 12 lanes to accommodate projected traffic demand. Because of the challenges associated with accomodating a much broader footprint withinthe existing corridor while minimizing impacts to neighboring property owners, the Tollway selected Hanson to lead the detailed design phase.
Working with its joint venture partners, the Hanson team prepared construction documents for 3.7 miles of tollway widening and reconstruction in five construction contracts, with a total construction value exceeding $300 million. Hanson was responsible for preparing construction documents for the approximately 2-mile section from just south of 47th Street to just north of Ogden Avenue (U.S. Route 34).
This section included replacing the bridge carrying I-294 over Flagg Creek and modifying the US 34 interchange. Three of the interchange’s four quadrants contain parks, with the village of Western Springs’ public works facility occupying the fourth. The Hanson-led team designed the mainline improvements and the bridge carrying I-294 over Flagg Creek.
The Burlington Northern Santa Fe (BNSF) bridge over I-294, a major feature of the Tollway’s master plan, was not designed by the Hanson-led team. However, Hanson performed the railroad coordination necessary to replace the bridge over I-294 during the master planning phase design and construction. This three-track BNSF rail corridor carries some of the heaviest rail traffic in the Chicago area, including freight and Metra commuter and Amtrack passenger service. The bridge replacement construction of a three-track shoo-fly because BNSF required the Tollway to maintain three tracks throughout construction.
Hanson also prepared construction documents for the replacement of the bridges carrying I-294 over I-55. Hanson was the designer of record for approximately $180 million in construction.
The client benefitted from relationships Hanson developed during the master planning phase with the stakeholders within the corridor, including the neighboringcommunities of Hinsdale and Western Springs, Illinois, and BNSF Railway. Throughout the design process, Hanson and the Tollway worked with stakeholders to minimize or avoid impacts associated with the improvements. Mitigation measures addressing concerns such as increased noise and adverse drainage impacts, were critically important to the success of the project.
