Intermodal traffic rose 6.4% last week from a year ago, the Association of American Railroads reported.
The gain was led by a 7.2% increase in container traffic to 203,744 units. Trailer traffic rose 1.9%, to 33,678 units.
Railroad carloads excluding intermodal edged up 0.3% for the week ended Saturday, to 290,181 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.