September Cass Data Suggests the U.S. Truckload Turn Is Still Strengthening

September freight data released on October 13, 2026 points to a more durable turn in the U.S. truckload market than many shippers saw over the summer. The latest Cass Transportation Index report for September 2026 showed the Cass Truckload Linehaul Index rising 10.1% year over year to 154.8, while the shipments component of the Cass Freight Index increased 1.9% year over year and 2.3% month over month. Cass said that was the second straight year-over-year gain in shipments after a 3.5-year downturn, the longest on record.

That combination matters because linehaul pricing excludes fuel surcharges. After months in which freight invoices were being pushed higher largely by diesel, September’s Cass data indicates the underlying truckload market itself is still firming. Cass also said freight demand is recovering on “modest retail and industrial growth” and some inventory restocking as container imports surge, while a smaller private fleet is supporting higher for-hire volumes.

What changed in the September Cass report

The headline figure is not just that trucking got more expensive. It is that base truckload pricing kept rising even after stripping out fuel. In its September report, Cass said the linehaul index was up 0.6% from August and up 10.1% from September 2025, adding that the index “reflects the whole for-hire truckload market, both spot and contract rates.” Cass also noted that the much larger contract market is still adjusting higher even as spot rates have cooled somewhat sequentially during bid-season lulls.

On volumes, the data is firmer than a “less bad” reading. Cass reported shipments were up 1.9% year over year in September and up 1.4% seasonally adjusted from August, building on a 5.0% sequential gain in August. The report cautioned that “two months generally does not make a trend,” but it also said “the cycle is on a positive track.” For industrial freight buyers, that is a meaningful shift from the earlier 2026 pattern, when rate strength was outpacing softer underlying shipment activity.

Why this looks different from a diesel-only story

Fuel is still a major part of the all-in freight bill. The U.S. Energy Information Administration said in its October 2026 Short-Term Energy Outlook that U.S. retail diesel prices averaged $6.29 per gallon in September, and forecast diesel would remain above $6 per gallon in October before easing gradually. EIA said distillate inventories were still tight, with East Coast stocks 32% below their five-year seasonal average in September. That keeps surcharge pressure alive even if wholesale markets cool later this quarter.

But the September Cass numbers matter because they isolate non-fuel pricing. A 10.1% annual increase in linehaul means the current freight-cost problem is increasingly two-layered: diesel remains expensive, and underlying truckload capacity is still priced tighter than a year ago.

That distinction is important for procurement teams that hoped late-summer inflation would prove temporary. If fuel alone were driving invoices, easing energy markets could quickly soften transportation spend. When linehaul is also rising, the market can stay costly even after surcharge pressure moderates.

Spot-market signals still point the same way

Weekly and monthly DAT data do not suggest a broad loosening. DAT’s Trendlines page showed its latest public weekly snapshot covering Sep. 28-Oct. 4, 2026 and comparing September 2026 with August 2026 and September 2026 with September 2025. DAT does not expose all current figures on the public page, but it continues to frame load-to-truck ratios as a real-time indicator of spot demand versus capacity and notes that rate direction typically follows changes in that balance.

The more detailed weekly DAT market commentary available from the prior month showed just how tight that balance had become. In data for Aug. 30-Sept. 5, 2026, DAT said truck posts rose after Labor Day, but equipment availability was still down double digits from a year earlier across van, reefer and flatbed. At that point, DAT put van, reefer and flatbed load-to-truck ratios at 11.5, 21.5 and 36.4, respectively, all far above the same week in 2025. It described the market as “still a supply-led market,” even with some weekly softening after holiday distortions. DAT’s 35-day forecast in that update also showed mid-October linehaul rates remaining well above year-ago levels for all three equipment types.

That broadly aligns with the Cass message: spot conditions may wobble week to week, but the market has not rebuilt enough usable capacity to restore the kind of slack that defined much of 2023 through 2025.

Capacity is still the central story, but demand is no longer absent

The most important analytical question is whether September’s turn is demand-led, supply-led, or both. The answer appears to be both, but with capacity still doing more of the work.

On the supply side, ACT Research said in its September 15, 2026 Freight Forecast update that the market remained “supply-constrained,” citing an ACT Driver Availability Index of 35.9 in August and spot equipment capacity at decade lows. Tim Denoyer, ACT Research vice president and senior analyst, said, “Tighter capacity and a modest improvement in demand are likely to keep upward pressure on freight rates over the next 12 to 18 months.” He also pointed to new broker liability laws, FMCSA driver rules, slow fleet growth, and replacement demand limiting how fast new truck capacity can return.

FreightWaves reported on October 7, 2026 that SONAR data showed tractors in new for-hire fleets falling to 19,520 in August, while the SONAR truckload rejection index held near 14%, roughly triple the range seen in the soft-market years from 2023 through 2025. Tender rejections are not a price index, but they are an operational service signal: when carriers reject more contracted loads, routing guides fail more often and recovery freight gets more expensive.

On the demand side, September’s Cass report is stronger than the summer narrative that rates were rising without much freight-volume help. Cass explicitly cited retail and industrial growth and some inventory restocking as container imports surge. The same report also projected North American intermodal loads to reach 19.3 million in 2026, which would break the prior 2018 record of 18.9 million, suggesting that freight demand is broadening rather than appearing in trucking alone.

Intermodal may still help, but it is not a free escape valve

One reason that matters is that tighter truckload conditions do not automatically make the network more resilient if freight shifts to rail. Cass and ACT said rail intermodal volumes are on track for a record year and quoted railroad executives saying they still have a cushion of capacity and are staging chassis for higher demand. That is constructive, especially for medium-haul freight where rail economics improve when truckload and diesel both stay elevated.

Still, record intermodal demand can create its own execution risk. If more freight is pushed off the highway to manage truck costs, bottlenecks can simply migrate into drayage, inland terminals, chassis pools, and rail handoffs. Intermodal remains an important option, but it should be treated as a network design decision, not as automatic relief.

Broader logistics indicators support the tighter-market reading

Other October data points released before the Cass report also pointed in the same direction. The September 2026 Logistics Managers’ Index, published on October 6, showed the Transportation Capacity Index falling to 34.4, indicating contraction for a tenth straight month, while the Transportation Prices Index rose to 92.7. That survey-based index is not a truckload-rate benchmark, but it is another sign that transportation buyers are still experiencing shrinking capacity and severe price pressure across the broader logistics system.

Taken together, the Cass, DAT, ACT, SONAR and LMI signals all point to the same operational reality: the market is not just expensive because diesel is high. It is expensive because capacity remains constrained at the same time that freight demand is improving enough to expose that constraint.

What this changes for Q4 and early-2027 planning

The practical implication is that transportation budgets now face more than a temporary fuel spike.

For shippers running dense routing guides, a firmer linehaul market raises the odds of higher primary-carrier nonacceptance, more mini-bids or repricing pressure, and more recovery freight moving at spot or near-spot levels. For project freight, heavy industrial inputs, construction materials, machinery components and plant-support shipments, the risk is not only higher cost per move but also longer lead times to secure dependable capacity, especially in flatbed-adjacent or specialized networks where supply has been tight for months.

The shift also matters for annual bid timing. If September turns into a third or fourth consecutive month of shipment growth, carriers and brokers will enter late-2026 and early-2027 procurement conversations with stronger rate confidence than they had this spring. If the volume rebound fades, the market could still cool somewhat. But September’s combination of positive shipment growth and double-digit linehaul inflation is stronger evidence of a durable turn than industrial buyers had even a month ago.

For readers tracking related CAP coverage, this is the clearest October evidence yet that record diesel prices are now hitting the freight invoice is no longer the full story. It also builds on the summer signal that truckload spot rates have moved above COVID-era highs and keeps open the question of whether intermodal is becoming shippers’ main escape valve from tight truckload.

For CAP Logistics readers, the near-term takeaway is straightforward: Q4 and early-2027 domestic freight plans should not assume summer’s inflation was only a surcharge event. Base truckload pricing is now moving higher too, which makes carrier selection, surge planning, routing-guide resilience and modal contingency planning more important than they looked a month ago.