Intermodal traffic rose 1.9% last week, the Association of American Railroads reported.
Container traffic rose 3.1% to 203,311 units from a year ago, while trailer traffic fell 4.9% to 32,257 units, AAR said.
Railroad carloads, excluding intermodal, edged up 0.4% for the week ended Saturday, to 287,321 units, AAR said in its weekly report.
Railroad volume is considered an important economic indicator. Intermodal traffic, which tends to be higher-valued merchandise than bulk commodities, uses trains for the long haul and trucks for the shorter distance at either end of the trip.