The Logistics Managers' Index climbed 3.6 points to 70.2 in September, the strongest reading in four years and a level the report's authors classify as a "significant rate of expansion." Any print above 50 signals industry growth, and the September result pushed the benchmark further into expansion territory as warehousing and transportation capacity contracted at the same time.

That dual squeeze translated directly into price. The transportation price index added nearly three points to reach 92.7, approaching historic highs. Researchers at Arizona State University, Colorado State University, Rochester Institute of Technology, Rutgers University, and the University of Nevada, Reno publish the monthly survey in conjunction with the Council of Supply Chain Management Professionals.

Where is the pressure concentrated?

Inventory accumulated faster than warehouses could absorb it. The LMI's warehousing capacity index fell to 39.3, its fastest contraction in four years. Inventory costs climbed to 79.9 — the third-highest reading in two years. Most of that stock sits upstream with wholesalers, awaiting shipment to retailers in the typical mid-October push that fills shelves before the holiday peak.

Transportation capacity mirrored the warehousing picture. The transportation capacity index slipped to 34.4, extending a ten-month run of contraction. With fewer trucks, railcars, and intermodal slots available, prices moved the other way. Shippers paid more per mile, per container, and per pallet as carriers held the leverage.

LMI researchers pointed to high "disruption-driven costs" as the central pressure on supply chains heading into peak season. They noted that aggregate logistics costs — a composite of inventory, warehousing, and transportation prices — reached their highest level since April 2022, "when supply-driven inflation was rampant in the wake of both the cessation of Covid-era demand and the invasion of Ukraine."

What does the capacity squeeze mean for shippers?

For shippers and forwarders, the data describe a peak season without the slack capacity that defined 2023. Tight warehousing means longer dwell times for imported goods moving through the largest US gateways. Tight transportation translates into rate increases on short notice and harder bargaining over demurrage and detention charges. Carriers, by contrast, sit on the favorable side of a market that has handed them pricing leverage for ten consecutive months.

The strain falls hardest on shippers that waited to move inventory. The LMI's sub-indices suggest wholesalers who deferred orders through the summer now compete for the same truck and slot capacity as retailers preparing for November and December demand.

How long will the pressure last?

Logistics managers surveyed expect the cost environment to persist. The Future Conditions Index registered 81.3 for inventory costs, 72.4 for warehousing prices, and 86.1 for transportation prices over the next twelve months — all well above the 50-point expansion threshold. That outlook aligns with current trajectory and points toward a holiday quarter shaped by scarcity rather than surplus.

The LMI tracks eight sub-categories across inventory levels and costs, warehousing capacity and utilization, and transportation capacity and utilization. September's print suggests the industry's post-pandemic expansion has matured into something more structural. Capacity has not kept pace with the inventory wholesalers have been quietly building since spring, and the October release will test whether mid-month shipping volumes finally relieve the warehousing backlog or extend the contraction into a fourth month.