"Monthly first quarter results were uneven due to the issues on the West Coast," said Joni Casey, president and CEO of IANA. "Despite February’s challenges, however, we still saw some overall quarterly growth, led by big boxes in regions less affected by port congestion."

Domestic intermodal results were particularly impressive in view of the challenges facing the import sector. A significant share of the freight carried by domestic intermodal is transloaded from 40-foot containers that come through a port. First quarter volumes exceeded the 5.1 percent gain recorded in Q4 of 2014.

Regional traffic growth remained tied to port issues, notwithstanding the relative strength of domestic intermodal. Volumes were down in the Southwest, which saw a 5.7 percent decline over Q1 2014. The Southeast surged 9.9 percent in Q1 2015, due to increases in both domestic and international containers. Western Canada posted the strongest growth rate of any region, jumping an exceptional 10.6 percent in Q1.

The seven largest volume corridors also varied according to their exposure to port disruptions. While lanes that included the Southwest were down, the intra-Southeast continued to be an intermodal powerhouse - intermodal shipments in that lane jumped 16.5 percent in a quarter-over-quarter comparison. Overall, high-density lanes, which accounted for 64.5 percent of total volumes, saw a minimal decline of 0.9 percent this quarter.

Intermodal marketing companies reported 3 percent growth in Q1, laying the groundwork for an even stronger performance in the coming months. Intermodal and highway loads jumped 3.2 percent and 2.6 percent, respectively. IMC highway gains were significant enough to push revenues up 1 percent, compared to Q1 of 2014.

Source: IANA