CTA Jefferson Park to O’Hare Signal Upgrades

New train control and communication systems were designed, fabricated, and installed on the CTA Blue Line from Jefferson Park Interlocking to O’Hare Interlocking, covering more than 16 miles of track. Signals were upgraded to allow for the removal of decade-old slow zones. The project also included track replacement in the O’Hare portal approach along with ancillary civil, structural, and mechanical work.