Completely rebuilt tracks on the Dan Ryan Line

Recent track renewal projects

Track renewal work is an ongoing effort for railroads, including the ‘L’ system. Over time, wear and natural aging of components can lead to conditions that require the implementation of slow zones pending repair or renewal efforts.

Regular maintenance

We perform regular maintenance and sometimes perform major track renewal/replacement projects to keep our system in safe, working condition—and to keep you moving quickly across town.

Learn more about regular maintenance and slow zone elimination

Recent, larger track renewal projects

Sometimes larger projects are done as a result of track conditions which have formed, other times they may be done because tracks in an area are due for replacement or even as a preventative measure.

Here are some of the more recent, larger track projects that have either eliminated or prevented slow zones or renewed tracks on our system...



Fast Tracks improvements map (notes savings on Red Line of up to 6 min, Blue 6 min, Brown 3 min, Green 3 min, Pink 2 min and highlights portions of routes where work will occur)

Beginning in early 2018, FastTracks addressed numerous “slow zones” where trains travel lower than optimal speed—fixing current slow zones and helping prevent others from occurring. To achieve this, crews replaced worn rail, rail ties and ballast, which are important to maintain the gauge of the track and support the trains’ weight, which made rides smoother, more comfortable and more reliable.

Also, electrical power improvements were made along the Blue Line O’Hare branch, which allowed us to run additional trains during high-ridership times—like the morning rush period on weekdays—to help address crowded trains and reduce the amount of time you have to wait on platforms.

This $179 million investment was funded through a small increase in fees charged to app-based ride-hailing companies operating in Chicago. The fee, proposed by the Mayor and approved by City Council in November 2017, was the first of its kind in the country to directly support investment in public transportation.

  • Green Line - South Side main line and branches (from near 18th south to and along both the Cottage Grove and Ashland branches)
  • Green and Pink lines on Lake Street 'L' (between Clinton and Ashland)
  • Blue Line - O’Hare branch (electrical power improvements)
  • Red Line subway (downtown State Street Subway)
  • Blue Line subway (downtown Dearborn Subway)
  • Blue Line - Forest Park Branch (Clinton to Forest Park)
  • Brown Line - Ravenswood Branch (Western to Kimball)

More information:


Ravenswood Connector Track Renewal

Brown Purple Lines, Armitage to Merchandies Mart
Work began in late 2013 on a $71 million project to perform major structural renewal and track improvement work on the Ravenswood Connector, the part of the Brown Line & Purple Line Express between Armitage and Merchandise Mart. Work, which continued through 2014, will eliminate about two miles of slow zones (as slow as 15 m.p.h.) on tracks that host 700 trains per day.

Work is now progressing on the second part of the project, upgrading signal systems across this part of the 'L'.


Your New Blue Track Work

Blue Line, Damen thru Belmont
In 2014, CTA began work to eliminate or prevent slow zones and reduce travel times on the Milwaukee Elevated portion of the Blue Line (which is the elevated line between Logan Square and Division) and in the Kimball Subway (through Logan Square and Belmont) and Dearborn Subway (Division through Clinton). The last major weekend closure for this work wrapped up at the end of August 2014.

This work was part of a major investment in the O'Hare Branch of the Blue Line, announced in December 2013 by Chicago Mayor Rahm Emanuel and Illinois Governor Pat Quinn. 

Learn more: 


Track work on Evanston Branch

Purple Line, Central thru Linden
Work to rehabilitate the tracks and remove slow zones was completed in December 2013 and included extensive tie replacement, placement of new ballast, and tamping of the track system and roadbed, when work finished between Milburn (near Central) and the north terminal at Linden. This followed work in a phase that was performed between Church and Milburn interlockings in the summer and fall of 2013.

This project was undertaken in several phases over the course of seven months using existing resources and was performed by CTA personnel in our Track and Structure departments. Work was performed overnight and on weekends and under single-track conditions (not requiring major track closures).


Dan Ryan Track Renewal (Red Line South Reconstruction)

Red Line, Roosevelt to 95th/Dan Ryan
From May thru October, 2013, we rebuilt the tracks along the South Side Red Line, from Cermak-Chinatown to 95th/Dan Ryan—a project that is providing faster, more comfortable and more reliable service for Red Line riders. Crews replaced everything in the track bed: ties, rail, third rail, ballast (the stone material that holds the ties in place) and drainage systems. The project included station improvements and made the remaining stations on Red South accessible to people with disabilities. Learn more...


North Side Main Line track work

Red Purple Lines, Belmont to Howard
Partial slow zone elimination was completed in 2008. Work was also completed in the area of Sheridan station, with slow zones around the station removed in December 2009. In 2010, work was completed eliminating existing slow zones between Addison and Wilson.

In late 2011, Mayor Emanuel and Governor Quinn announced a $1 billion investment in the Red Line, which included some track and tie replacement and viaduct repair work on the North Side Main Line, eliminating approximately 7,000 feet of slow zones and speeding up service on the Red Line and Purple Line Express.

Much of this work was done as part of the Red North Station Interim Improvements project, plus work in the summer of 2015 to replace track ties and the restore track alignment to eliminate slow zones between Lawrence to Jarvis on the outer Purple Line Express tracks.


Track work on Ashland Branch (Englewood)

Green Line, 59th Junction to Ashland/63rd
...also used by Red Line trains during Red Line South Reconstruction Project and certain rush hour trains during work at 95th/Dan Ryan station renovations

Significant work was done to eliminate slow zones in Spring 2013, including track tie replacement work, on the South Side Green Line in anticipation of rerouted Red Line service to Ashland/63rd during track renewal on the Dan Ryan line.


Loop Track Renewal, Wells Street Bridge Replacement and Hubbard St. Curve work

Loop Elevated, downtown, and Brown Line and Purple Line Express
In 2012 and 2013, the second phase of major work was done to ensure safe and efficient operations on the Loop ‘L’, focusing on the Wells and Van Buren legs of the Loop, replacing tracks, ties and other elements. Major work was performed on and near both Loop junctions (Towers 12 and 18).

The earlier phase of Loop Track Renewal was completed in 2008 on the Lake and Wabash sides of the Loop.

The Wells Street Bridge, which leads into the Loop from the north, was replaced by the Chicago Department of Transportation (with the bridge and our tracks over the bridge reconstructed) in 2013 and the tracks on top of it, used by Brown Line and Purple Line Express trains, were completely rebuilt.

During the Wells Street Bridge replacement, work proceeded to replace Tower 18 (Wells/Lake junction), as well as work to repair and eliminate slow zones just north of the Loop and Merchandise Mart at the Hubbard St. curve.


Purple Line Viaduct Replacements

In September 2011, work began on the $15.5 million Purple Line Viaduct project, which will reduce slow zones and improve travel times for Purple Line customers by replacing three aging viaducts along the line at Greenleaf, Dempster and Grove streets in Evanston. Viaduct work also includes new abutments, retaining walls, foundations, and new waterproofing and drainage systems. Other project work includes rail tie replacement, new landscaping and lighting enhancements under the bridges.

Replacement of the three viaducts was complete this summer. The majority of project work completed by May 2013.


State Street Subway track renewal

Red Line, North/Clybourn thru Roosevelt
Work was done in the area between north portal of the State Street Subway (north of North/Clybourn) and Roosevelt. Almost 3.5 miles of slow zones were eliminated until completion in 2008.

Work was also done in February 2013 to eliminate slow zones by making track improvements across a handful of locations in the State Street Subway that needed maintenance from regular wear & tear and some heat damage sustained in 2012.


O'Hare-Kennedy track renewal

Blue Line, O'Hare Branch between Addison and O'Hare
Track renewal and slow zone elimination work was completed in December 2008. Over 21 miles of track were renewed and over 18 miles of slow zones were eliminated.


Dearborn Subway track renewal

Blue Line, Division thru Clinton
Slow zone elimination in the Dearborn Subway began during 2007 and 2008, when track tie replacement and other improvements were made between the Dearborn Subway's north portal (located between Damen and Division) and Clark/Lake to eliminate existing slow zones that were substantially impacting travel times.

The first phase of work resulted in the replacement of over 5,000 deteriorated wooden track ties with concrete ties in areas where slow zones existed.

A larger project funded by the Federal American Recovery and Reinvestment Act during 2009 and early 2010 upgraded tracks and track ties along the full length of the Dearborn Subway, from Damen to UIC-Halsted. Many track components in the subway, including aging track ties, were replaced to provide even more reliable service in the future.


Track renewal on elevated Ravenswood Branch

Brown Line, Ravenswood Branch from Southport to Western
Slow zone elimination completed October 2008 included major tie replacement work to eliminate slow zones through the elevated portions of the Brown Line's Ravenswood Branch.

System status snapshot
‘L’ route status
Red Line
Normal Service
Blue Line
Normal Service
Brown Line
Normal Service
Green Line
Normal Service
Orange Line
Normal Service
Pink Line
Normal Service
Purple Line
Normal Service
Yellow Line
Normal Service
Bus routes w/alerts
Elevator alerts