WASHINGTON, D.C. - The Association of American Railroads (AAR) today reported U.S. rail traffic for the week ending September 17, 2016. For this week, total U.S. weekly rail traffic was 537,904 carloads and intermodal units, down 5.1 percent compared with the same week last year.  Total carloads for the week ending September 17 were 270,336 carloads, down 5.3 percent compared with the same week in 2015, while U.S. weekly intermodal volume was 267,568 containers and trailers, down 4.9 percent compared to 2015. Three of the 10 carload commodity groups posted an increase compared with the same week in 2015. They were miscellaneous carloads, up 21.2 percent to 11,104 carloads; farm products excl. grain, and food, up 4.9 percent to 16,544 carloads; and chemicals, up 1 percent to 30,723 carloads. Commodity groups that posted decreases compared with the same week in 2015 included petroleum and petroleum products, down 17.4 percent to 11,633 carloads; forest products, down 13 percent to 10,013 carloads; and coal, down 12.5 percent to 90,369 carloads. For the first 37 weeks of 2016, U.S. railroads reported cumulative volume of 9,191,535 carloads, down 10.8 percent from the same point last year; and 9,540,513 intermodal units, down 3.2 percent from last year. Total combined U.S. traffic for the first 37 weeks of 2016 was 18,732,048 carloads and intermodal units, a decrease of 7.1 percent compared to last year. North American rail volume for the week ending September 17, 2016, on 13 reporting U.S., Canadian and Mexican railroads totaled 361,991 carloads, down 3.4 percent compared with the same week last year, and 339,537 intermodal units, down 3.3 percent compared with last year. Total combined weekly rail traffic in North America was 701,528 carloads and intermodal units, down 3.4 percent. North American rail volume for the first 37 weeks of 2016 was 24,496,523 carloads and intermodal units, down 6.8 percent compared with 2015. Canadian railroads reported 77,273 carloads for the week, up 3.7 percent, and 61,593 intermodal units, up 3.5 percent compared with the same week in 2015. For the first 37 weeks of 2016, Canadian railroads reported cumulative rail traffic volume of 4,772,966 carloads, containers and trailers, down 6.4 percent. Mexican railroads reported 14,382 carloads for the week, down 2.5 percent compared with the same week last year, and 10,376 intermodal units, down 0.2 percent. Cumulative volume on Mexican railroads for the first 37 weeks of 2016 was 991,509 carloads and intermodal containers and trailers, down 2.4 percent from the same point last year.