U.S. railroads moved 565,502 carloads and intermodal units during the week ending May 26, marking a 4.4 percent increase over the same week last year. Total carloads ticked up 3 percent to 273,226 units during Week 21, while intermodal traffic grew 5.8 percent to 292,276 containers and trailers, according to Association of American Railroads (AAR) data. Eight of the 10 carload commodity groups that AAR tracks on a weekly basis posted increases compared with the same week in 2017. They included chemicals, up 2,474 carloads to 33,674; coal, up 2,088 carloads to 84,674; and metallic ores and metals, up 1,519 carloads to 25,939. Commodities that slipped during the week included motor vehicles and parts, down 846 carloads to 16,874; and miscellaneous carloads, down 845 carloads to 9,417. Meanwhile, Canadian railroads logged 83,017 carloads for the week, up 9.3 percent over the same period in 2017. They also moved 66,190 intermodal units, up 4.4 percent. Mexican railroads reported 20,752 carloads and 17,983 intermodal units. Year-over-year comparisons for Mexican railroads won't be available until Week 27 due to Grupo Mexico's acquisition of Florida East Coast Railway in July 2017. For the first 21 weeks of the year, U.S. railroads reported cumulative volume of 5,414,483 carloads, up 1.2 percent year over year, along with 5,736,006 intermodal units, up 5.9 percent from last year. Total combined U.S. traffic for 2018's first 21 weeks was 11,150,489 carloads an intermodal units, a 3.6 percent increase over 2017. Canadian railroads logged 3,081,648 carloads, containers and trailers for the first 21 weeks of the year, marking a 3.4 percent gain. For their part, Mexican railroads moved 795,968 carloads and intermodal containers and trailers during the first 21 weeks.