---
title: "Chicago Transit Authority (CTA) Red-Purple Modernization Project – Chicago, Illinois"
url: "https://www.systra.com/ibt/project/chicago-transit-authority-cta-red-purple-modernization-project-chicago-illinois/"
type: projects
date_published: 2022-01-01
date_modified: 2026-05-15
schema:
  @type: WebPage
language: en-US
word_count: 420
reading_time: 3 min
canonical: "https://www.systra.com/ibt/project/chicago-transit-authority-cta-red-purple-modernization-project-chicago-illinois/"
featured_image: "https://www.systra.com/ibt/wp-content/uploads/sites/21/2022/01/cta_systra-ibt-viz_rendering1.jpg"
project-market:
  - Transit Bridges
  - Segmental Bridges
project-location:
  - USA
---

# Chicago Transit Authority (CTA) Red-Purple Modernization Project – Chicago, Illinois

![Chicago Transit Authority (CTA) Red-Purple Modernization Project – Chicago, Illinois](https://www.systra.com/ibt/wp-content/uploads/sites/21/2022/01/cta_systra-ibt-viz_rendering1.jpg)

## DESIGN-BUILD

**Total Length: **15,442 m (50,660 ft)

**As part of the Walsh-Fluor Design-Build Team, SYSTRA International Bridge
Technologies developed a segmental concrete guideway for a major portion of
The US$2 billion Red-Purple Modernization project in Chicago.

This design required approval of an alternate technical concept that
significantly improved upon the baseline steel design. This is the first
segmental structure built by the Chicago Transit Authority (CTA). The CTA
operates the famous Chicago ‘L’ (short for “Elevated”) rapid transit system,
which first began service in 1892 and is well-known for its steel structures.

**Significant factors for the concept’s approval included:**

- Improved means to address difficult construction equipment access
- Compressed construction schedule
- Reduced initial construction cost
- Reduced maintenance cost

During the pursuit, SYSTRA IBT showcases distinctive visualization capabilities.
The realistic renderings were incorporated in the reviews of the alternate
technical concept and were a key factor in communicating the design,
construction, and aesthetic concepts to the CTA and the public.

The SYSTRA Bridge Group, SYSTRA Consulting USA, and SYSTRA-DTE also collaborated
for this pursuit. In addition to bridge engineering, the team deploys its
worldwide rail systems and transit expertise. Due to the unique character of the
proposed structure within the Chicago system, it was necessary for SYSTRA to
develop a unique stray current protection system that effectively protects both
the new closed-deck segmental structure and the adjacent open-deck steel
structures.

The ‘L’ is the second busiest rail mass transit system in the United States, and
it is an iconic symbol of Chicago. This is a very high-profile win for SYSTRA in
North America.

## Featured Project

Some examples of projects in Segmental Bridges, Transit Bridges

[  Surrey Langley SkyTrain – Langley, BC, Canada ](https://www.systra.com/ibt/project/surrey-langley-skytrain-langley-b-c-canada/)
[  Hart Metro, Contract 3 – Honolulu, Hawaii ](https://www.systra.com/ibt/project/hart-metro-contract-3-honolulu-hawaii/)
[  Mosquito Road Bridge – El Dorado County, California ](https://www.systra.com/ibt/project/mosquito-road-bridge-el-dorado-county-california/)
[  Reseau Express Metropolitain (REM) – Greater Montréal, Canada ](https://www.systra.com/ibt/project/reseau-express-metropolitain-rem-greater-montreal-canada/)
[  Davenport Diamond Guideway Project – Toronto, Ontario, Canada ](https://www.systra.com/ibt/project/davenport-diamond-guideway-project-toronto-ontario-canada/)
[  Sound Transit East Link Extension I-90 Crossing – Seattle, Washington ](https://www.systra.com/ibt/project/sound-transit-east-link-extension-i-90-crossing-seattle-washington/)

[ See a selection of SYSTRA's projects ](https://www.systra.com/ibt/project/sound-transit-east-link-extension-i-90-crossing-seattle-washington/)