U.S. freight-rail traffic plunged 22.1 percent to 412,549 carloads and intermodal units during the week ending May 9 compared with the same week a year ago, Association of American Railroads (AAR) data shows. Railroads logged 185,144 carloads, down 28.4 percent, and 227,405 containers and trailers, down 16 percent. None of the 10 carload commodity groups that AAR tracks on a weekly basis posted increases. Among the commodity group decreases posted during the week, coal was down 34,111 carloads to 46,515; motor vehicles and parts were down 14,876 carloads to 2,108; and metallic ores and metals were down 7,513 carloads to...