Despite month-to-month variations, third quarter intermodal freight traffic growth of 3.4% was in line with year-to-date results, according to new figures from the Intermodal Association of North America (IANA).

The international market segment showed some volatility as its volumes climbed 3.3% in July and 6.4% in August, then slowed to 1.6% growth in September. Nevertheless, the segment closed the quarter with a 4% increase, almost even with the 4.1 percent growth in domestic containers.

“The international market segment normalized this quarter after dealing with the lingering effects of first quarter port congestion that were still felt during the second quarter,” said Joni Casey, president and CEO of IANA. “Overall we are seeing international container trends approaching pre-recession levels and domestic volume gains returning to numbers that are comparable to international.”

The domestic trailer market segment, which includes the U.S, and Canada, shrunk 3.1% in a quarter-over-quarter comparison, making the third quarter the fifth consecutive quarter of dipping trailer volumes. This deflated the quarterly gains realized in total intermodal loads, according to IANA. However, September domestic container growth of 6% helped boost overall domestic numbers.

The seven highest-density trade corridors, accounting for 66% of total intermodal volume, rose 3.7% this quarter, exceeded the industry average. Growth rates for each individual corridor varied widely. The intra-Southeast corridor, positively affected by stronger imports and rising market share over trucking, experienced gains of over 20%. Meanwhile, the South Central-Southwest corridor volumes decreased by 5.9%, with international particularly affected.

Regional traffic growth was overall positive in the third quarter, despite significant losses in the South Central region and slight declines in Western Canada. The South Central area’s 9.2% decline is largely the result of a fall in international shipments. The Northwest and Southeast regions countered with substantial volume increases in the third quarter, rising 9.9% and 9.1%, respectively.

Intermodal marketing companies (IMCs) demonstrated clear growth in market share during a period of depressed freight output. Highway loadings shot up 10% while intermodal loadings rose by just under 2%, combining to produce an overall volume increase of 5.2%. However, revenue decreases in both highway and intermodal loadings, resulting in a 3% decline, yielded mixed results for IMCs this quarter.