Norfolk Southern Corp. plans to lay off an undisclosed number of employees as part of an effort to cut costs, company spokesman Robin Chapman confirmed Friday.

The Norfolk-based railroad also will reduce the number of trains in operation and park some rail cars, he said. The cuts are an effort to cope with weak rail traffic volumes, Wick Moorman, Norfolk Southerns chief executive, told The Wall Street Journal in an interview published Thursday.   Norfolk Southern employs about 30,200 people across its rail network, which spans the eastern half of the United States.

The company is not releasing additional details regarding the layoffs or other cost-saving measures at this time, Chapman said.