U.S. freight volumes are running about 1.5% above year-ago levels, but nearly all of that growth sits in three sectors tied to data center construction — machinery, fabricated metals and steel — leaving the broader market vulnerable if the AI buildout cools, Dr. Jason Miller of Michigan State University said in a video interview.

How exposed is freight to the data center pipeline?

Miller drew a direct parallel to the hydraulic fracturing boom that peaked in 2014 and collapsed into the 2015-2016 industrial recession. The next six to nine months of data center construction are already "baked in," he said. Beyond that window, community opposition, AI company finances and rising interest rates could slow the pipeline.

He flagged Oracle's force majeure declaration on a New Mexico project with Blue Owl Capital as an early warning. OpenAI and Anthropic face mandatory compute payments next year that their revenues may not cover, he added.

"My concern is that if we start to see next year any type of significant slowdown in the data center ecosystem while we still have a very weak single-family housing ecosystem, that would be very bad news from a freight demand standpoint," Miller said.

The non-AI side of freight is weakening in parallel. Food and beverage demand is down 3% to 4% year-over-year, pressured by GLP-1 drug adoption, weaker discretionary spending, three-year-high wheat prices and retaliatory tariffs on U.S. exports.

Why is trucking capacity holding in a 'Goldilocks' band?

Tender rejection rates sit around 14%, well below the roughly 28% weekly-average peak seen during the 2021 boom, Miller said. That level is tight enough to support contract rate increases for asset carriers without igniting a capacity surge.

Three forces removed supply:

• Three consecutive bad years for carriers in 2023, 2024 and 2025
• English-language proficiency and non-domiciled CDL enforcement actions
• The Supreme Court's May ruling in Montgomery v. Carbide, which stripped broker liability protections under state tort law

Diesel above $4 per gallon is acting as an additional brake on capacity re-entry heading into 2027, Miller said.

What is dragging consumer sentiment below crisis levels?

"The vibes are not good for the consumer," Miller said, pointing to Conference Board sentiment data that fell sharply in September. He attributed much of the malaise to housing affordability.

The median home price sits at roughly $390,000 to $400,000, a gap between qualifying income and median household income that did not exist in 2017-2019. Flatbed carriers dependent on single-family housing starts should plan for a weaker spring 2026 ramp, he warned.

Could policy push freight into a 2027 slowdown?

Two more Fed rate hikes — one in October and one in December — would erase all the cuts made at the end of last year, Miller said. That trajectory risks a material freight demand contraction in 2027.

A return to large-scale military conflict involving Iran could push energy prices higher, force the Fed to raise rates further and compound demand weakness across the freight market, he added.

Miller said the current dynamic mirrors 2011-2014, when freight demand grew but bypassed most consumers, keeping sentiment depressed even as GDP expanded.

Shippers and brokers should treat the next 6-9 months of data center starts as the leading indicator: a slip beyond that window, combined with two additional Fed hikes and continued housing weakness, would expose how thin the base is beneath today's 1.5% volume growth.