The Chicago Transit Authority has released the draft environmental impact statement for a proposed 5.3-mile-long extension of its Red Line train. Part of the agency’s multiproject Red Ahead program, aimed at modernizing Chicago’s primary north-south rail line, the extension would mostly parallel an existing Union Pacific freight corridor, south from the current Red Line terminus. Approximately two-thirds of the extension will be on elevated structures. Four new stations are to be added as part of the project, as well as a new rail yard and shop. Among the issues yet to be resolved is the extension’s alignment relative to the freight corridor. CTA expects to finalize the Red Line extension’s alignment next year in preparation for issuing a final EIS in 2018. The project is expected to cost at least $2.3 billion, with a three-year construction phase slated to begin by 2022.