Up to 700 more layoffs may be on the way for Jacksonville-based CSX.
CEO Hunter Harrison made the announcement Wednesday during an earnings call.
There is no specific timeline and no specific information about where the positions might be eliminated, CSX officials said.
The workforce has already been trimmed by 2,300 employees.
The fleet has been trimmed by 900 locomotives and could be trimmed 100 more.
The railroad started the year with 12 hump yards and could end with three, Harrison estimated.
Other efficiencies include lengthening trains and bringing contracted work back in house.
Harrison told analysts during the call that his tenure with the company would be short.
"I'm a short-timer here," Harrison said. "I'm the interim person that's going to try to get this company to the next step and good foundation."
CSX officials said during the meeting that the railroad's operating ratio, a key measure of efficiency, improved from 69.4 percent for 2016 to 67.4 percent for the quarter. Revenue climbed 8 percent.
"It’s important to note that CSX is NOT just reducing headcount as a way of improving efficiency -- we are changing the way the railroad operates, which is resulting in greater operational efficiencies (fewer trains moving more freight faster) which sometimes also results in a reduction in the number of employees required to operate the railroad," CSX spokesperson Rob Doolittle said.