Cook County will begin construction to replace the 170th Street bridge over Thorn Creek on or around November 24. The project will be completed in stages to keep traffic moving as much as possible.
Project Timeline
Fall 2025 – Spring 2026: Pre-Stage Work
During this first phase, crews will remove the median and make pavement repairs. Drivers should expect occasional, temporary lane closures.
Spring 2026 – Summer 2026: Stage 1
Construction will focus on rebuilding the north half of the bridge. Traffic will be shifted to the south half, where one lane in each direction will remain open.
After Stage 1 – Through 2027: Stage 2
Once the north side is complete, traffic will move to that side while crews replace the south half of the bridge. Again, one lane in each direction will stay open throughout this stage.
The County currently expects the entire project to be finished in 2027.
What to Expect
Although one lane in each direction will remain open at all times, residents should be prepared for lane closures, traffic delays, and other restrictions throughout the project. Motorists and pedestrians are encouraged to use caution in the work zone or consider taking alternate routes.