Total intermodal freight volumes gained 4.5% in the second quarter of the year, the strongest growth in nearly three years, according to new figures from the Intermodal Association of North America.

International freight once again was the primary driver, rising 5.6%. Domestic containers and trailer volumes increased 3.2% and 3.9%, respectively.

"Growth in the second quarter indicates that economic conditions continue to improve for all segments of the intermodal market,” said Joni Casey, president and CEO of IANA. “Year-to-date performance is a healthy 3.3%, notwithstanding a weak year-over-year comparison for the second quarter."

Intermodal service providers again demonstrated clear gains in the intermodal sector. While highway loads declined 3.4%, intermodal volumes were up 5.8% for the quarter. The net result was a 0.6% improvement over the same period last year.

The seven highest-density trade corridors, accounting for 63.4% of total intermodal volume, collectively were up 4% in the second quarter. The Trans-Canada lane led the way with an 11.4% expansion, while the Midwest-Northwest, down by 0.6%, experienced the only decline. The remaining five corridors' growth in the second quarter ranged from a 1.3% to 4.6% improvement.

Of these seven lanes, five stood out in terms of directional activity, accounting for 42.9% of the three-month results. The Southwest-Midwest direction took the lion's share with 10.6%. Western Canada-Eastern Canada and the Eastern Canada-Western Canada both came in at 9.2%, while the Midwest-Southwest route added 7.4%. The final in the top five, the Northeast-Midwest, accounted for 6.5%.