"We are still seeing increases in imports, partly because last year's volumes made for easy comparisons and partly because of real improvements in the economy and consumer spending," said Jonathan Gold, NRF's vice-president for supply chain and customs policy.
“We're still going to see increases in container volume, but not as large as what we've seen so far. As retailers head into the peak shipping season, they will also to need to address challenges they are currently facing with lack of vessel capacity and with labour and congestion issues at some of the ports."
US ports handled 1.25 million TEU in May, the latest month for which actual numbers are available. That was up 10 percent from April and 20 percent from May 2009. It was also the sixth month in a row to show a year-on-year improvement after December broke a 28-month streak of year-on-year declines.
"The latest economic indicators are starting to look bleak, including consumer confidence, industrial production and employment numbers," said Ben Hackett, founder of consulting firm Hackett Associates.
"Sales will be slower in July and August; that much is certain. Inventories will rise, resulting in some sharp seasonal volume reductions."
Hackett says some of the current surge in container volume reflects the fact that shipping companies have recently restored some of the services that were cut back during the recession of the past two years.