CATEGORY: Transportation

PROJECT FIRM: Bowman Consulting Group, Ltd., H.W. Lochner, Inc., HDR Engineering, Inc, and Quigg Engineering, Inc.

OTHER CONSULTANTS: American First Contracting, Inc., Bowman Consulting Group, Ltd., Christopher B. Burke Engineering, Ltd., Geo Services, Inc., Himalayan Consultants, LLC, M Squared Engineering, LLC, TranSystems, SDIENGR Corp., SE3, Thomas Engineering, LLC, 2IM Group, LLC, Accurate Group, Inc., Alfred Benesch & Company, Ames Engineering, Inc., Angelo Construction Services, Inc., CKL Engineers, LLC, INTERRA, Inc., J.A. Watts, Inc., Juneau Associates, Inc., Millennia Professional Services, Nashnal Soil Testing, LLC, Orion Engineers, LLC. Peralte-Clark, LLC, Program Management & Control Services, LLC, Terra Engineering Ltd.

OWNER: Illinois Tollway

DESCRIPTION: The Tri-State Tollway (I-94/I-294/I-80), built in 1958 to bypass Chicago and connect Illinois, Indiana and Wisconsin, is a crucial transportation route. It generates more than 44 percent of the Illinois Tollway’s $1.5billion annual revenue and moves more than 150,000 vehicles daily. The Mile Long Bridge Project is central to the $4 billion rebuilding and widening of the 22.5-mile Central Tri-State Tollway (I-294). This project, totaling $500 million, involved replacing and widening the complex structure while keeping existing traffic lanes open. A dedicated team of design and construction engineering firms went above and beyond to achieve outstanding results. The Mile Long Bridge includes two side-by-side bridges that span two railroads, three waterways, local roads and major UPS and BNSF Railway distribution centers. This project involved replacing two 65-year-old structures with two five-lane bridges that include improvements in environmental features, stormwater management, active traffic management and flex lanes to meet the Tollway’s long-term needs. Flex lanes will be used to accommodate transit during heavier travel periods and various safety-related needs in case of emergencies. The project began in spring 2019 with construction of the new northbound bridge east of the existing one. The new northbound bridge was completed in November 2020. The old northbound structure was then demolished, and a new southbound bridge was constructed and finished in November 2022.The remaining demolition and restoration work occurred while Tollway customers continued to use the new northbound and southbound bridges without disruption. A crucial design feature was use of fewer and longer spans for each bridge (from 54 spans to 27 spans each), reducing the impact on the sensitive aquatic ecosystem, navigable waterways, railroads and roads below. This approach also minimized the number of deck joints and the incorporation of stainless-steel reinforcement in the decks, parapets and piers resulted in an exceptionally durable end-product. This reduced the need for regular maintenance and extended the service life to 100 years. By designing the bridges on a new alignment, safety was maximized and disruption to Tollway customers during construction was minimized. Final deck finishing and the elimination of longitudinal deck joints further enhanced the bridges’ durability. Construction engineers actively promoted the engineering profession and improved public perception by offering numerous project site visits, which were open to project stakeholders, elected officials, highschool students from underrepresented areas and college students throughout construction. Social, economic and sustainability factors were incorporated into the project by recycling all materials from the old structure, creating opportunities for small and disadvantaged engineering and construction firms, improving navigation on the Chicago Sanitary Ship Canal below (the third busiest commercial waterway in the country) and ensuring access to the busiest national UPS and BNSF intermodal yards. The project presented unique challenges, including relocating ComEd high-tension transmission towers, moving 4,500 feet of a 14-inch high-pressure Buckeye jet fuel line for two international airports, installing the longest precast concrete beams in the Midwest, managing deck stormwater and fulfilling commitments to six nearby communities, eight regulatory agencies, utilities, railroads, businesses and property owners. This involved coordination of 69 consulting firms and 109 construction contractors. The Mile Long Bridge Project surpassed the owner’s expectations by delivering a cost-effective solution that maintained traffic throughout. It was finished on time and within budget, in line with the Tollway’s program goals. Impressively, this success was achieved due to the dedicated design and construction engineering teams even during the peak of the COVID pandemic. They quickly implemented new safety measures to ensure uninterrupted progress.