Rail carload and intermodal traffic fell sharply for last week of 2007 compared with the same week a year earlier, the Association of American Railroads said.
Intermodal traffic fell 8.2% to 158,726 trailers and containers, AAR said in its weekly report.
Container volume fell 6.7% to 125,547 units, while trailers plunged 13.5% to 33,179 units.
Overall rail carload traffic rose 4.8% from a year ago to 255,560 carloads, the group said.
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.