Four ways to read US freight
Freight is the oldest real-time proxy for the goods economy. Four independent measures cover it — trucking, rail, ports and road miles — and they answer different questions about whether things are moving.
At a glance
| Measure | Latest | Period | Published by | Frequency |
|---|---|---|---|---|
| Cass Freight Index — shipments | 1.04 | Aug 2026 | Cass Information Systems | Monthly |
| Rail carloads and intermodal | 532,905 Railcars | Sep 16, 2026 | Association of American Railroads / Surface Transportation Board | Weekly |
| Port of Los Angeles container throughput | 955,906.5 TEU | Aug 2026 | Port of Los Angeles | Monthly |
| Vehicle miles travelled | 278.12 Billion miles | Jul 2026 | Federal Highway Administration | Monthly |
How each one is built
- Cass Freight Index — shipments
- Method: Freight bills processed by Cass on behalf of shippers, base January 1990 = 1.00
- Covers: Mostly truckload and less-than-truckload North American domestic freight
- Released: Around the middle of the following month
- Rail carloads and intermodal
- Method: Physical count of cars originated, by commodity group
- Covers: Class I railroads; coal, grain, chemicals, motor vehicles and intermodal containers
- Released: Weekly, within days
- Port of Los Angeles container throughput
- Method: Twenty-foot equivalent units loaded and unloaded
- Covers: The largest US container gateway — a proxy for transpacific import demand
- Released: Mid-month
- Vehicle miles travelled
- Method: Estimated miles driven on all US public roads
- Covers: All traffic, not only freight — but the truck share tracks goods movement
- Released: About two months later
Volume, price and direction
Cass publishes both a shipments index and an expenditures index. Shipments count how much moved; expenditures count what was paid. Dividing one by the other gives an implied rate per shipment, which is often a better read on trucking market tightness than either index alone.
Rail and ports split the story geographically. Port container volumes lead the domestic goods cycle by a month or two because imports must be unloaded before they are trucked inland; intermodal rail then picks them up. Coal and grain carloads move on entirely separate logic — weather, exports and power generation — so the commodity breakdown matters more than the total.
Which one to use
For the domestic goods cycle, use Cass shipments, which has the longest continuous history and covers the trucking market that carries most US freight.
For timeliness, use weekly rail: it is a physical count published within days and is not an estimate of anything.
For import demand specifically, use container throughput at the major ports. And treat vehicle miles travelled as a measure of all road activity, not of freight — it moves with commuting and fuel prices as much as with goods.
Frequently asked questions
- Is the Cass Freight Index a volume or a price measure?
- Cass publishes both: a shipments index measuring volume and an expenditures index measuring spending. Their ratio gives an implied freight rate.
- Why watch rail carloads by commodity rather than the total?
- Coal, grain and intermodal respond to completely different drivers. A fall in coal carloads driven by power generation says nothing about the consumer goods cycle.
- How far ahead do port volumes lead domestic freight?
- Typically one to two months, since imported containers must be unloaded before they enter domestic rail and trucking networks.
- Does vehicle miles travelled measure freight?
- Not on its own. It covers all road traffic including passenger cars, although the truck share of the data does track goods movement.
