AAR noted 15 of the 20 carload commodity groups it measures posted increases compared with the same week in 2011. Gaining commodities included petroleum products, up 71.5%, crushed stone, sand,and gravel, up 29.5%, and lumber and wood products, up 27.3%. Declining commodities included metallic ores, down 26.3%, and coal, down 11.1%. Coal's relative decline has been a key factor in lower U.S. freight carload volume for the year.

Weekly carload volume on Eastern railroads was up 5.8% compared with the same week last year. In the West, weekly carload volume was down 2.1% compared with the same week in 2011.

Canadian freight carload volume rose 2% during the week ending Dec. 22 compared with the same week last year, while Canadian intermodal volume advanced 3.7%. Mexican freight carload volume soared 14.5% ahead of the comparable week in 2011, while Mexican intermodal did even better, up 16%.

Combined North American freight carload volume for the first 51 weeks of 2012 on 13 reporting U.S., Canadian, and Mexican railroads was down 1.8% measured against the comparable period in 2011. Combined North American intermodal volume for the period was up 4.4%.