Chicago Red and Purple Line: Rebuilding a Transit Lifeline for the Next Century

The Red and Purple Line corridor in Chicago, Illinois, spans 9.6 miles of track. Built between 1900 and the 1920s, much of the infrastructure had reached the end of its service life, requiring frequent repairs and creating costly slow zones. In response, the Chicago Transit Authority (CTA) launched the $2.1 billion Red and Purple Line Modernization project to revitalize this critical transit artery.

Jacobs, as part of the ESP Joint Venture with Arcadis and Ardmore Roderick, served as the owner’s representative for Phase One, coordinating the complex design-build delivery. Our team provided project management, field support, quality oversight, risk management and project controls.

A modern transit system built for the future

Phase One included the full reconstruction of the Lawrence, Argyle, Berwyn and Bryn Mawr stations — making them fully accessible for the first time — and the replacement of adjacent tracks and support structures. Wider platforms, improved lighting and modern amenities enhance riders' experience.

A major milestone came in 2021 with the completion of the Red-Purple Bypass north of Belmont Station. This new structure allows northbound Brown Line trains to pass over Red and Purple Line tracks, eliminating a key bottleneck and enabling more frequent service. 

In July 2025, Jacobs joined CTA and its ESP Joint Venture teammates to mark the grand opening of the rebuilt tracks, structures and stations in the Lawrence to Bryn Mawr Modernization Project. These improvements delivered larger, Americans with Disabilities Act (ADA)-accessible stations with modern amenities, real-time information, improved lighting and security, and smoother, more reliable service — all designed to reduce delays, ease overcrowding and create a more welcoming pedestrian experience.

Delivering lasting benefits for Chicago

Beyond the rail upgrades, the program improved local roads and utilities, including sewer and water service, to minimize disruptions and enhance neighborhood resilience.

Working with CTA on one of the most ambitious transit upgrades in its history, our team focused on:

• Collaborative design-build delivery: Jacobs brought in experts familiar with CTA standards to manage risk and maintain quality throughout one of the largest design-build projects in CTA history.
• Community engagement: In dense urban neighborhoods, Jacobs helped monitor construction impacts, track concerns and coordinate mitigation strategies to keep residents informed and involved.
• Leading technical knowledge: From bridge and systems engineering to signaling and utilities, our team provided real-time support and constructability reviews to keep the project moving forward.
• An eye on safety: With heavy equipment operating near active rail and pedestrian areas, safety remained the top priority. Full-time safety managers, supported by rail-certified and Occupational Safety and Health Administration (OSHA)-trained staff, ensured that every worker returned home safely each day.