NS's fourth-quarter operating revenue of $2.7 billion was down 4% from the comparable quarter in 2011. The company's 2012 revenue of $11 billion slipped 1% below the 2011 total.

The railway operating ratio increased 3% to 73.4% during the fourth quarter, and rose 1% to 71.7% for 2012, compared with the same periods of 2011, the company said.

"While the fourth quarter reflected declines in coal shipments, we also saw steady intermodal volume gains coupled with improved volumes in our chemicals, auto, and housing sectors," said Norfolk Southern CEO Wick Moorman.

"We remain focused on controlling costs and improving productivity while continuing to provide high service levels for our customers. In 2013, we plan to invest $2 billion in capital improvements to further our strong safety performance, improve operational efficiency and service, and support future growth," Moorman said.