MARTA on Thursday said it will seek proposals for the final design of a proposed 15.5-mile bus rapid transit line in Clayton County.

The metro Atlanta transportation agency wants to operate a BRT line roughly from MARTA’s College Park station to the Southlake Mall area.

If created, the Southlake BRT line would parallel much of MARTA’s bus route 196 and have about “13 stations with rail-like amenities, such as off board fare payment, level boarding, seating and digital signage,” MARTA said.

“Total project cost right now is at $338 million,” Lawrence Prescott, MARTA interim chief of capital programs, planning and innovation, told the MARTA board Thursday. He added that the figure could grow to “$380 million with some of the alternative alignments depending on the options.”

MARTA is seeking architectural and engineering services in the final design and is breaking the work up in segments north and south of I-285.