Mile Long Bridge Planning, Design and Construction

The Mile Long Bridge is a key link for regional freight and public transportation located in Willow Springs, Illinois (suburban Chicago). The new 4800 foot long bridges are part of the Illinois Tollway’s Move Illinois program and opened to traffic in November 2020 (northbound) and October 2022 (southbound). The bridges carry five lanes of the Tri-State Tollway (I-294) in each direction over railroads, a multi-modal freight hub, three water bodies and the 75th Street interchange. The 1957 era bridges were widened multiple times to meet increasing traffic demands (150,000 vehicles daily).

Unique project aspects include the length, the variety of surrounding features, and construction methods. Project challenges included maintaining vehicular and rail traffic during construction with limited access and available right-of-way, while minimizing impacts beneath the structures. The planning and design accommodated the restricted construction methods, contractor access, soil conditions, and major utilities which influenced the locations where piers could be placed. The new bridges feature the longest prestressed concrete spans (187 feet) and longest steel spans (410 feet) on the entire Tollway system. Every drop of water that falls on the bridges is routed through stormwater “best management practices” for filtering of pollutants before being released into waterways. The presentation will cover the unique planning, design and construction challenges - including public process, environmental, sustainability and resiliency - that were successfully met by a multi-disciplined team working collaboratively with the Tollway.

Additional Project Information can be found at:
https://www.illinoistollway.com/projects/tri-state/mile-long-bridge-project

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