In an effort to eliminate nearly 4 miles of slow zones and repair over 10 miles of 40-year-old deteriorated track, the Chicago Transit Authority selected Kiewit Infrastructure and Aldridge to completely rebuild the south branch of the Red Line.

Over a 154 day extended line cut, where the Dan Ryan Red Line was shut down, Aldridge performed the removal, rehabilitation and installation of over 20 miles of traction power 3rd rail and cable and 145 miles of signal and communications cable. Aldridge's detailed scope included the installation of over 10 miles of 16-cell express ductbank; 400,000 linear feet of new signal, traction power and communications cable; removal, rehabilitation and installation of existing signal equipment for 10 miles of track (including 10 interlockings); installation of 13,400 3rd rail chairs; and 20 miles of auxiliary negative return rail, as well as a complete testing and commissioning program for the Signal, Communications and Traction Power Systems. The scope also included a complete rebuild of the Cermak Junction, where the Dan Ryan Red Line Connects to the Elevated Orange Line Structure.