The CTA previously announced the $2.1 billion, Red and Purple Modernization Program (RPM). Now, the transit agency has three developers lined up to submit proposals, according to Railway Technology.

The three developers will submit proposals for the first phase of RPM, which includes designing and rebuilding four Red Line stations: Argyle, Berwyn, Bryn Mawr, and Lawrence. Chicago Rail Constructors, Kiewit Infrastructure Company, and Walsh Fluor Design-Build Team are the three selected developers, according to the report.

The CTA expects to begin construction on the first phase of the project in 2019, according to the report. The project will generate approximately 5,700 jobs.

The RPM also includes the construction of the Belmont flyover, a bypass track at the Belmont Brown Line stop.

The CTA will carefully evaluate the proposals from the three developers before making its choice.

“It is critical that we find the most qualified builders in the industry to construct this project, which is one of the biggest modernization projects in CTA history,” said CTA President Dorval Carter Jr., according to the report.