The National Retail Federation now expects cargo volume to total 15.3 million TEU (20-foot equivalent units) for the year, a 7.1 percent decline from last year. A month ago, the trade group foresaw a 6.5 percent drop in yearly retail cargo traffic, with total cargo volume being the lowest since 2005.

With retailers attempting to avoid unplanned post-holiday markdowns, “the balance between supply and demand is tougher than ever,” said Jonathan Gold, vice-president for supply chain and customs policy, in a statement.

The trade group foresees a mere 2.2 percent growth in holiday season sales – the lowest predicted increase since 2002 – and “one of the slowest years in quite some time for retail stores,” said J. Craig Shearman, vice-president of government affairs.

According to the National Retail Federation, after major growth in 2005 and 2006 – by about 9.8 and 6.7 percent, respectively – retail cargo volume peaked over the past six years at 16.5 billion TEU in 2007.

Though such a decline in traffic is significant, the year’s total volume still amounts to growth in volume since 2004, said Andrei Roudoi, IHS Global Insight manager of international trade forecasting.

Both Roudoi and the National Retail Federation predict that, once the holiday season ends, a still-strengthening U.S. dollar could help amount to a 2.3 percent growth next March. But “it is really too soon to say whether March will be an indication of any sort of trend” for the year, Shearman said.