Congress Parkway Bridge Rehabilitation

The Congress Parkway Bridge is a dual double-leaf, trunnion-type bascule bridges spanning over the South Branch of the Chicago River, carrying both eastbound and westbound traffic on Congress Parkway. Originally built in 1956, this movable bridge is one of the busiest bridges in Illinois and located in the heart of Chicago. The purpose of the project was to improve the Bridge Condition & Load Rating by rehabilitating the bridge’s structural, electrical, and mechanical elements.

Selected by the Illinois Department of Transportation (IDOT), TYLin provided a range of services, including construction inspection, contract administration, coordination, and materials quality assurance testing. We also coordinated shop drawing review, monitored traffic control, verified the contractor’s layout, prepared required documentation, coordinated material testing, and more, all in accordance with IDOT procedural guidelines.

Project challenges included replacing an open grid deck with an orthotropic “closed deck” system. Due to existing truss conditions and elevations, the fabrication and erection of the orthotropic deck required the development of revised attachment details to allow for nominal shimming and field adjustment.  

Project Highlights:

• Safety improvements included installing a closed deck system with a skid-resistant surface, enhanced lighting, and surveillance equipment.  
• Replacing the deck system required counterweight analysis and design modifications due to a significant increase in the closed system deck weight. 
• Structural rehabilitation included floor beam and truss repairs. 
• Mechanical work removed all tie shaft machinery and replaced the center lock machinery, machinery brakes, barrier gates, and traffic gates.  
• Electrical work included replacing the main drive motor, the current control system with a programmable logic controller (PLC) control system, facility lighting, power distribution panels and switchgear, cable and conduit routing, and traffic signals.