CTA Blue Line

Chicago, Illinois

The Forest Park branch of the Chicago Transit Authority (CTA) Blue Line, built in the late 1950s, connects downtown Chicago with the Illinois Medical District (IMD). After more than six decades of heavy use, most of the track components along the branch were still in service beyond their useful life. Nearly 70% of the Congress Branch Blue Line required slow zones to accommodate deteriorating drainage and subgrade conditions, leading to significant delays and a diminished rider experience.

The Blue Line Congress Trackwork Rehabilitation project was the first phase of the CTA’s Forest Park Branch Rebuild, a multi-year, multi-phased investment to make service faster, safer, more reliable and more accessible for all Blue Line riders. Major elements of the project included the installation of an improved drainage system, new sub-ballast and trackwork and a conduit duct bank and cables for communications and signal systems. Inside the subway tunnel, the scope included complete crack injection, rail and rail plate replacement, drainage improvements and tunnel cleaning from LaSalle to the Subway Portal.

Read more about the CTA Blue Line project on Kiewit Newsroom.