AAR reported mixed rail traffic for the week ending Feb.23, 2013, with total U.S. weekly carloads of 278,059 carloads, down 1.2 percent compared with the same week last year. Intermodal volume for the week totaled 238,083 units, up 11 percent compared with the same week last year.  Total U.S. traffic for the week was 516,142 carloads and intermodal units, up 4.1 percent compared with the same week last year. Four of the 10 carload commodity groups posted increases compared with the same week in 2012, led by petroleum products, up 66.4 percent. Commodities showing a decrease included grain, down 17.3 percent and metallic ores and metals, down 10 percent. For the first eight weeks of 2013, U.S. railroads reported cumulative volume of 2,169,628 carloads, down 4.6 percent from the same point last year, and 1,902,470 intermodal units, up 7.3 percent from last year. Total U.S. traffic for the first eight weeks of 2013 was 4,072,098 carloads and intermodal units, up 0.6 percent from last year. Canadian railroads reported 77,789 carloads for the week, up 1.3 percent compared with the same week last year, and 51,389 intermodal units, up 12.6 percent compared with 2012. For the first eight weeks of 2013, Canadian railroads reported cumulative volume of 609,662 carloads, up 1.8 percent from the same point last year, and 407,429 intermodal units, up 5.5 percent from last year. Mexican railroads reported 16,475 carloads for the week, up 12.4 percent compared with the same week last year, and 10,669 intermodal units, up 12.3 percent. Cumulative volume on Mexican railroads for the first eight weeks of 2013 is 115,031 carloads, up 8.4 percent from the same point last year, and 73,912 intermodal units, up 0.1 percent from last year.Combined North American rail volume for the eight weeks of 2013 on 13 reporting U.S., Canadian and Mexican railroads totaled 2,894,321 carloads, down 2.8 percent compared with the same point last year, and 2,383,811 trailers and containers, up 6.8 percent compared with last year.