Intermodal volume in the first quarter of 2016 increased, underscoring the segment's core strengths despite other indicators, according to the Intermodal Association of North America’s latest report.

While intermodal trailer volume declined more than 24%, overall volumes netted a 2% total growth for the quarter. Trailer volumes represent the smallest portion of total intermodal shipments, so a decline in that segment was not indicative of intermodal health as a whole, according to IANA.

Domestic container loads recorded a 6.4% increase. Combined with a 3.8% gain in international volumes, the entire segment showed growth in the quarter.

"Total container shipments, domestic and international combined, rose approximately 5% during the first quarter of this year," said Joni Casey, president and CEO of IANA. "And while influenced by comparisons to last year when we were dealing with port congestion issues, we're cautiously optimistic about this year's growth potential."

The seven highest-density trade corridors increased by 4.7% in the quarter. While some corridors fared better than others, all were in the positive. The Midwest-Northwest corridor had the largest growth in the quarter with 10.1%, reflecting the strength of both international and domestic containers, according to IANA.

Weaker international container imports showed negative growth in regions like Mexico, while trailer declines affected areas on a regional level. Intermodal Marketing Companies again demonstrated clear gains in the highway sector, up 15.4% from the previous year, thanks to excess trucking capacity. Intermodal loads fell 13%. The net result was a volume decrease of 1.1%.

A more extensive breakdown of the intermodal industry is contained in the Intermodal Market Trends and Statistics report published quarterly by the IANA. The IANA is an industry trade association that represents the combined interests of the intermodal and freight industry.