North America intermodal freight volume in May increased 4.4% year-over-year, with domestic share surpassing international.

North American Intermodal May Data: Domestic Share Dominates, International Weak

According to the latest data from the Intermodal Association of North America (IANA), North American intermodal freight volume in May 2026 increased by 4.4% year-over-year to 1,618,761 units, reversing the 0.6% year-over-year decline in April. This growth was primarily driven by demand for domestic containers and trailers, while the growth rate of international containers slowed significantly.

Performance by Category

• Trailers: 39,839 units, up 7.9% year-over-year
• Domestic Containers: 783,590 units, up 8.6% year-over-year
• All Domestic Equipment (including trailers and domestic containers): 823,429 units, up 8.6% year-over-year
• ISO International Containers: 795,332 units, up a slight 0.4% year-over-year

January-May Cumulative: Slight Overall Increase, International Containers Decline

• In the first five months of 2026, total North American intermodal freight volume reached 7,725,501 units, up 0.8% year-over-year. Among them:
• Domestic containers cumulative: 2,957,463 units, up 5.1% year-over-year
• Trailers cumulative: 152,139 units, down 2.1% year-over-year
• All domestic equipment cumulative: 3,109,602 units, up 4.8% year-over-year
• ISO international containers cumulative: 2,997,138 units, down 4.7% year-over-year

Structural Shift: Domestic Share Surpasses International

Andrew Sibold, IANA's Economic Director, pointed out in a conference call in early June that the Iran conflict has had a significant impact on domestic intermodal transportation. In March and April, the domestic intermodal share exceeded 50%, marking the first time in years that domestic accounted for more than international. Sibold stated: "Since January, the domestic share has consistently dominated, which breaks the historical pattern of intermodal transportation."

Sibold analyzed that rising fuel prices (diesel pushed up by the Iran conflict) have prompted some long-haul truck freight to shift to intermodal, while tariff-induced import weakness and a recovery in domestic manufacturing have also driven this structural change. He said: "The recovery of domestic manufacturing is partly thanks to AI data center construction investments and the federal settlement act last summer, which stimulated corporate investment in domestic manufacturing."

Tightening Truck Capacity Creates Window for Intermodal

Larry Gross, President of Gross Transportation Consulting, noted that intermodal is currently facing two independent factors: international imports are sluggish due to tariffs, while domestic freight benefits from rising fuel costs and tightening truck capacity. Gross added: "Government regulatory actions regarding English proficiency, non-resident commercial driver's licenses, and 'zombie truck drivers' have tightened truck capacity supply and raised rates, providing a conversion opportunity for intermodal."

Outlook

As truck capacity continues to tighten and the effects of domestic manufacturing investments emerge, intermodal may continue to maintain a domestically dominated structure.As truck capacity continues to tighten and the effects of domestic manufacturing investment become apparent, multimodal transport may maintain its domestically dominated structure. However, the weakness in international containers indicates that import demand has not yet recovered. If the Iran conflict eases, leading to lower fuel prices, or if tariff policies are adjusted, the landscape could shift again. Sibold said, "The subsequent developments are worth watching."