But the mixed picture for U.S. freight traffic rolled on during the week ending Feb. 16, 2013, AAR said, with freight carload volume for the week down 1.2% measured against the comparable week in 2012, while U.S. intermodal volume, a significant driver of 2012 U.S. freight traffic, advanced 13.6%.

Only three of the 10 carload commodity groups AAR measured posted increases compared with the same week in 2012, with petroleum products continuing its upward climb, up 56.1%, followed by nonmetallic minerals and products, up 12.1 %. Commodities showing a decrease were led by grain, down 14.3%.

Canadian freight carload traffic fared better than its U.S. counterpart, up 1.5% for the week ending Feb. 16 compared with the same week in 2011. Canadian intermodal also did well, up 5.7%. Mexican freight carload traffic rose 11.% for the week compared to a year ago, while Mexican intermodal volume for the week was 7.7% higher than in the comparable 2012 period.

Combined North American freight carload volume for the seven weeks of 2013 on 13 reporting U.S., Canadian, and Mexican railroads was down 3.2% measured against the comparable period in 2012, while combined intermodal volume was 6.1% greater