Transit officials Thursday released the latest details of a $2.3 billion plans to extend CTA’s Red Line south from 95th Street to 130th Street, fixing on two route options near existing railroad tracks.

The extended Red Line would veer west from the Dan Ryan Expressway at the current southernmost stop at 95th Street, following the right-of-way of Union Pacific tracks threading through West Pullman and Roseland, according to maps released Thursday. The transit agency plans to settle on one route or the other by next year.

CTA officials are seeking input from residents on two proposed courses, one following along the west side of the railroad tracks, the other, to the east. CTA officials in 2014 ditched another route that would have run elevated tracks along South Halsted.

Both options call for elevated tracks to be built from 99th Street to 118th Street, either just east or just west of the Union Pacific right-of-way. The routes are the same from the 95th Street stop to 99th Street, and both also call for the extended Red Line to run on at-grade tracks from 119th to 135th Street.

The east option would require the CTA to acquire 175 homes and businesses along the route, while the west course would impact 113 privately-owned properties, spokesman Jeffrey Tolman said Thursday.

The 5.3-mile extension would add four stations to the Red Line South spur — near 103rd Street, 111th Street, Michigan Avenue and 130th Street.

CTA next week will release a draft of an environmental impact report listing the costs and benefits of each proposed route, and CTA staffers will begin going door-to-door in neighborhoods in the path of the extension, Tolman said. Copies of the report will be posted online at http://www.transitchicago.com/redeis, and hard copies are available at a half-dozen city library branches and CTA headquarters, 567 W. Lake Street.

Transportation activists and South Side leaders have called for extending the Red Line’s southern spur roughly from the time construction of the 95th Street terminal was completed in 1969, though a proposed route along Halsted unveiled in 2014 was met with criticism.

Whatever the route, the first tracks won’t be laid this decade, Tolman said. It will take until 2018 to submit final plans and studies to federal transportation agencies, and assembling the land in the footprint of the new tracks will take more years still. The earliest construction might begin is 2022, Tolman said.

At least some funding for the extension will likely come from federal grants for new mass transit construction, and the city also might consider a tax-increment financing district, or TIF, to pay for the construction, CTA spokeswoman Tammy Chase said.

The CTA on Thursday released two possible routes for an extended Red Line. | Chicago Transit Authority

The CTA on Thursday released two possible routes for an extended Red Line. | Chicago Transit Authority