The project will completely rebuild the tracks and track bed on the 10-mile stretch of the Red Line known as the Dan Ryan Branch.
"The South Red Line is a vital link to communities from Chinatown to Roseland and beyond and this project will set the foundation for smooth, reliable train service for decades to come," CTA Board Chairman Terry Peterson said.
CTA President Forrest Claypool added, "Once this work is complete, our customers will be riding on a brand new railroad. Their commutes will be faster, their rides will be smoother and more comfortable and they'll see fewer service interruptions thanks to better reliability."
In spring 2013, CTA will close the South Red Line from Cermak-Chinatown to 95th Street for five months, affecting nine stations.
The five-month construction option will save $75 million over an option to perform work on weekends only. That $75 million savings will be reinvested into station upgrades along the south Red Line, such as three new elevators, lighting, painting, electrical substation work and other improvements and will also enable CTA to provide the extensive alternative service during construction.
A weekends-only option would take four years to complete and would also impact tens of thousands of customers each week on the line that sees the highest number of weekend customers. Weekend ridership on the Red Line is two thirds that of weekday ridership.
The reconstruction will shave 20 minutes off the round-trip between 95th Street and Roosevelt.
The work will replace all the ties, rails, third rail, drainage systems and ballast. The nine stations along the branch will receive improvements ranging from new lighting and paint to new bike racks. Elevators will be added at Garfield, 63rd and 87th Streets, making the entire South Red Line accessible.
The project is part of Mayor Rahm Emanuel's Building a New Chicago infrastructure renewal program. Funding for the work is part of more than $1 billion in federal, state and local funding announced in late 2011 by Chicago Mayor Rahm Emanuel and Illinois Governor Pat Quinn for the Red and Purple lines.