Import retail shipping traffic at major U.S. ports shot up 23 percent in August, compared with year ago levels, and should continue to rise in the coming months due to improvements in the U.S. economy, according to a report by the National Retail Federation research firm Hackett Associates.

U.S. ports handled 1.42 million 20-foot cargo container units or equivalent in August, the latest month for which data is available, a rise of 3 percent compared with July.

The Global Port Tracker report estimated the number of 20-foot cargo containers or equivalent units handled in U.S. ports had risen by 20 percent year-on-year in September and would rise by 11 percent over year-ago levels in October. (See table below)

"Import volume last year was very low and that's why we're expecting such growth in October on a year-over-year basis," said Ben Hackett of Hackett Associates.

"We've mostly been seeing positive indications. Annual average import volume grew by 16 percent in 2010 compared to last year. This came as retailers restocked after the collapse of inventories, U.S. industries imported more manufacturing inputs and consumer spending improved," he added.

The report also said that the peak import season, when retailers stock for the holiday season, shifted to August in 2010, a month earlier than usual.

"This came because retailers imported goods earlier than usual and the decline we expect in the coming months is only a seasonal downturn," Hackett added.

The Global Port Tracker report covers Los Angeles, Long Beach, Oakland, Seattle, and Tacoma ports on the West Coast; New York, New Jersey, Hampton Roads, Charleston and Savannah ports on the East Coast, and Houston on the Gulf Coast.

MONTH UNITS SHIPPED(TEU) CHANGE VS YEAR AGO
August 1.42 million 23
September* 1.37 million 20
October* 1.32 million 11
November* 1.21 million 11
December* 1.12 million 3