Intermodal traffic rose 11.9% for the last week of 2010 compared with the same week a year earlier, the Association of American Railroads said.
Traffic for the week ended Jan. 1 totaled 166,894 units, led by an 18.1% in trailers to 25,248 units. Containers rose 10.9% to 141,646 units.
Intermodal traffic for the full year totaled almost 11.3 million trailers and containers, up 14.2% from 2009.
U.S. railroads originated 240,073 carloads for the week, up 5.6% from a year ago and 7.3% for the year, to 14.8 million units.
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.