With a mild 0.6 percent gain in the latest week, major North American railroads again set a new all-time high in intermodal loadings with 313,026 containers and trailers in the week ending Oct. 1.

That was 1,901 boxes more than in the week ending Sept. 24, when the Association of American Railroads first said major Class I and regional carriers had set a new weekly record for intermodal volume.

In addition, the carriers last week picked up 4.1 percent more boxes than in the same week of 2010, an acceleration from recent year-over-year gains. This comes after a summer slowdown in containerized imports and predictions of a sluggish autumn peak season for intermodal traffic on the continent’s railroads. However, retailer expect intermodal-related sales to be up mildly from 2010 levels.

The AAR said the North American majors loaded 276,522 containers in the Oct. 1 week, up 4.8 percent from the same week of 2010. Trailer loadings fell 1 percent year-over-year to 36,504 units in the latest week.

For the first 39 weeks of 2011, the large railroads have seen intermodal volume grow 5.3 percent, with a 5.6 percent rise in container traffic and 3 percent gain in trailers.

— Contact John D. Boyd at jboyd@joc.com. Follow him on Twitter www.twitter.com/jboydjoc