Intermodal traffic increased 17.3% last week from a year earlier, the highest volume in 2010, the Association of American Railroads said.
Traffic for the week ended Saturday totaled 241,167 trailers and containers, led by a 19.2% jump in containers to 206,535 units. Trailers rose 7% to 34,632 units.
Overall intermodal traffic was fell 2.1% from the same week in 2008, but containers rose 6%. Trailers were down 32.8% from two years ago.
U.S. railroads originated 300,908 carloads for the week, 10.7% higher than a year ago but down 8.2% from 2008, 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.