Volume at major container ports bumped up significantly in November, as retailers imported merchandise ahead of new tariffs set to take effect this month, according to the Global Port Tracker report released by the National Retail Federation, Washington, D.C., and Hackett Associates, Alexandria, Va.

Imports at the nation’s major retail container ports are expected to increase 4.6% during the first half of 2017 over the same period last year, as the nation’s economy improves and retail sales continue to grow.