U.S. intermodal traffic declined 2.8% for the week ended Saturday from a year ago, the Association of American Railroads reported.
Container traffic dipped 1.5% to 184,703 units, while trailers dropped 9.9% to 29,699 units.
Railroad carloads excluding intermodal fell 5% to 281,644 units, the rail trade group 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.