North American intermodal transportation is undergoing a structural shift: domestic share historically surpasses international, as the dual impact of tariffs and energy reshapes the logistics landscape.

North American Intermodal Sees Structural Shift: Domestic Share Surpasses International Historically

According to the latest data released by the Intermodal Association of North America (IANA), total intermodal container volume in North America reached 1.619 million units in May 2026, a year-over-year increase of 4.4%, reversing the 0.6% decline in April. However, the more noteworthy aspect is the structural reorganization behind the numbers: domestic containers (including trailers) grew by 8.6%, while international ISO containers grew by only 0.4%. The share of domestic equipment in total volume has exceeded 50% for the first time on a stable basis, marking a new phase in North America's logistics model.

Three Major Drivers: Energy, Tariffs, and Labor Policy

In a conference call earlier this month, IANA Economic Director Andrew Sibold pointed out that the ongoing conflict in Iran continues to push up diesel prices, significantly increasing the cost of long-haul trucking and prompting shippers to accelerate their shift to rail intermodal. At the same time, the "One Big Beautiful Bill" signed by the White House last year incentivizes domestic manufacturing investment, particularly the demand for equipment and materials transportation driven by AI data center construction, providing a new cargo base for domestic intermodal.

But the most direct impetus comes from tariffs. Sibold explained that a year ago, massive tariff-driven advance imports created a high base, while imports have shrunk significantly this year, with international container volume declining 4.7% cumulatively in the first five months. Tariffs have not only suppressed total import volume but also forced a regional restructuring of supply chains, with some goods previously covered by international transport being replaced by domestic production, further supporting domestic intermodal.

Tight Truck Capacity Creates Window of Opportunity

Larry Gross, President of Gross Transportation Consulting, noted that two independent factors are currently at play simultaneously: the suppression of the international side due to sluggish imports, and the boost to the domestic side from fuel and labor. He specifically highlighted supply-side changes in the trucking industry—federal regulations strengthening English language requirements, restricting non-resident Commercial Driver's Licenses (CDLs), and cracking down on "zombie truckers"—which have led to a large amount of unqualified capacity exiting the market.

"Tight truck capacity has pushed up full truckload rates, creating a window of opportunity for intermodal to capture truck conversions," Gross said. "We are already beginning to see the effects in our domestic data."

Short-Term Disruption or Long-Term Trend?

Despite strong indicators, analysts remain cautious about sustainability. Sibold acknowledged uncertainties in diesel price fluctuations and tariff policy directions. In the May data, international containers still recorded a slight 0.4% increase, indicating that imports have not completely collapsed. In addition, the AI construction boom and legislative stimulus may be one-time pulses rather than sustained growth engines.However, Gross believes that the likelihood of a long-term increase in the share of domestic intermodal transport is growing. The structural impact of stricter truck capacity regulations will not fade quickly, and while tariff-driven manufacturing reshoring is controversial, corporate investment decisions often exhibit inertia. If energy prices remain high, the competitiveness of domestic intermodal transport will continue to strengthen.

Implications for the Global Logistics Landscape

This structural shift in the North American market also holds reference value for Europe and other regions. In an era where geopolitical conflicts, trade policy games, and energy transition overlap, transportation modes are no longer driven solely by economic efficiency; policy interventions and external shocks are becoming decisive variables. The development of intermodal transport in Europe similarly faces challenges such as a shortage of truck drivers, cost changes brought about by the Carbon Border Adjustment Mechanism (CBAM), and energy price volatility. The North American case shows that when policy and price signals converge, shippers' behavioral adjustments may be faster and more persistent than expected.

In the coming months, IANA data will reveal the resilience of this trend. If the share of domestic equipment continues to operate above 50%, it would mean that North American intermodal transport has entered a new normal dominated by domestic traffic, which will reshape the competitive and cooperative relationships among railways, trucks, and ports, and have profound implications for infrastructure investment directions.