Triple 14 — Monday, September 14, 2026

TL;DR — the day in rail + freight.

• The most recent AAR weekly data on the board is week 35 (ending Sept. 5): 533,545 total U.S. carloads and intermodal units, up 13.8% year over year, with intermodal at 299,148 units (+18.0%) and carloads at 234,397 (+8.9%) [1][2].
• Discount that headline. AAR's August monthly read had intermodal averaging nearly 297,000 weekly containers and trailers, up only 4.4% YoY — a monthly record, but nowhere near +18% [3]. Week 35 laps a weak Labor Day 2025 base; the ~4% line is the demand signal to plan against.
• Nine of ten carload groups rose YoY in week 35; coal was the lone decliner, off 3,547 cars to 58,037 [1]. Metallic ores/metals, grain and chemicals drove the gain.
• No rate data, no Class I service advisories, and no port dwell or chassis figures are sourceable this cycle — see those sections. Do not price off a number you cannot trace.
• Regulatory item with teeth: STB's final rule in EP 724 (Sub-No. 5) adds certain chemical and plastics traffic as a distinct category in the Class I weekly cars-held metric — useful evidence for any shipper building a service-failure record on chem or plastics tank cars [4].

Market snapshot — rail + intermodal rates, volumes, capacity.

Volumes are the only half of the picture that is verifiable today. Week 35 U.S. traffic totaled 533,545 carloads and intermodal units, +13.8% YoY, split 299,148 intermodal units (+18.0%) and 234,397 carloads (+8.9%) [1][2]. Carload gains were broad: metallic ores and metals +4,859 to 23,122, grain +4,373 to 22,509, chemicals +3,848 to 33,653; coal alone fell, down 3,547 to 58,037 [1]. Year to date through 35 weeks, U.S. railroads have moved 7,986,328 carloads (+2.8%) and 9,904,325 intermodal units (+4.2%), for 17,890,653 total units (+3.6%) [1][2]. North American traffic for the week was 727,511 units, +12.4%, with Canadian carloads +10.4% and Mexican carloads −7.4% [1].

Read the weekly number against the monthly. August intermodal averaged almost 297,000 weekly units, up 4.4% YoY and a new monthly record [3] — the July 4 holiday week showed the same distortion in the other direction (482,121 units, +8.7%, intermodal +12.9%) [5]. The consistent interpretation is a mid-single-digit intermodal growth trend with holiday-week comps producing noise on both sides. Treat +18% as a calendar artifact, not a capacity event.

On rates and capacity: no rail, intermodal or truck rate benchmarks appear in the fetched sources this cycle, and neither AAR nor STB publishes rates. Any pricing view today has to come from your own Cass, DAT or IMC/carrier quote data — nothing here supports a number.

Service advisories — Class I disruptions: weather, derailments, labor, maintenance windows.

No material development in the fetched sources this cycle.

Port congestion — major ports (LA/LB, NY/NJ, Savannah, Houston): dwell, backups, chassis.

No material development in the fetched sources this cycle.

Regulatory — STB rulings, demurrage rules, tariffs, policy.

The actionable item is STB's final rule in Petition for Rulemaking to Amend 49 C.F.R. Part 1250, Docket EP 724 (Sub-No. 5), which establishes certain chemical and plastics traffic as a distinct reporting category within the Class I weekly service metrics on cars held [4]. For shippers in those commodities, that converts an anecdote into a filed, carrier-reported number — worth pulling when negotiating service commitments or documenting a failure.

Also on the Board's rail service data page: STB is collecting data from the Belt Railway Company of Chicago pursuant to a Board letter dated Aug. 3, 2026, and maintains a dedicated resources page for the proposed Union Pacific–Norfolk Southern merger [4]. Nothing in the fetched sources this cycle addresses demurrage rulemaking outcomes or tariff actions.

Signals worth watching — what to track next.

1. This week's AAR release (week 36). The test is whether intermodal holds near the ~297,000 weekly average and whether the YoY compresses back toward +4% once the Labor Day base washes out [1][3].
2. Coal. The only carload group in decline in week 35, off 3,547 cars against a 58,037-car base [1]. A second and third down week changes the network's car-supply and crew picture more than any single intermodal print.
3. Class I weekly service filings. Train speed, terminal dwell, cars online, cars not moved 48+ hours and trains held by cause are the fluidity read that AAR volumes cannot give you — and the place to check your specific lane [4].
4. Chicago gateway. STB's carrier filings include Chicago gateway car counts and trains held short of Chicago, plus the new Belt Railway data collection [4]. With volumes elevated, that is where tightness surfaces first.
5. UP–NS merger docket. STB is running a dedicated resources page for the proceeding [4]; filings there are the primary record, ahead of trade-press summaries.

Sources

1. AAR reports rail traffic for the week ending September 05, 2026 — AJOT, Sep 10, 2026 — https://www.ajot.com/news/aar-reports-rail-traffic-for-the-week-ending-september-05-2026
2. US freight railroads logged increased traffic in week 35 — Progressive Railroading, Sep 10, 2026 — https://www.progressiverailroading.com/intermodal/news/US-freight-railroads-logged-increased-traffic-in-week-35--77719
3. U.S. rail carload and intermodal momentum continues in August, reports AAR — Logistics Management, Sep 10, 2026 — https://www.logisticsmgmt.com/article/u.s_rail_carload_and_intermodal_momentum_continues_in_august_reports_aar
4. Rail Service Data — Surface Transportation Board — https://www.stb.gov/reports-data/rail-service-data/
5. U.S. Rail Traffic Surges 8.7% in Holiday Week Ending July 4, 2026 — American-Rails.com, Jul 10, 2026 — https://www.american-rails.com/railtrafficweek26.html