U.S. freight carload traffic, struggling throughout this year to equal 2011 levels, was a winner in the latest week, up 0.4% over the comparable week last year. U.S. intermodal volume continued its winning streak, up 3.3% over 2011.

AAR said 13 of the 20 U.S. carload commodity groups posted increases compared with the same week in 2011, led by petroleum products, up 56.3%, lumber and wood products, up 29%, and grain, up 11.2%. Pacing the declining commodities were iron and steel scrap, down 19.7%, metallic ores, down 13.3%, and farm products excluding grain, down 13.2%.

Canadian freight carload volume for the week advanced 6.8% compared with the same week last year, while Canadian intermodal volume did even better, up 12.7%.

Mexican freight carload volume rose 9.1% compared with the same week last year, while Mexican intermodal rose 18.4%.

Combined North American freight carload for the first 31 weeks of 2012 on 13 reporting U.S., Canadian, and Mexican railroads still lagged behind 2011's pace, down 1.3%. Combined North American intermodal moves, however, were up 4.6% for the period compared with last year.