How a 10% Intermodal Volume Surge is Testing the US Freight Rail Network

The US freight rail network is currently experiencing the industrial equivalent of a sudden, massive rush hour. Since Memorial Day 2026, the volume of intermodal shipping—the movement of large shipping containers that transfer seamlessly between ships, trains, and trucks—has surged by double digits across the country.[1]

According to data from the Association of American Railroads, intermodal traffic reached nearly 289,000 containers and trailers in a single week in late June, representing a 12.1% increase compared to the same period in 2025. This influx of freight is a positive indicator of economic activity and supply chain reconfiguration, but it is testing the physical limits of the nation's rail infrastructure.[3]

The immediate consequence of this volume windfall has been a predictable drop in network fluidity. Data reported to the Surface Transportation Board shows that average intermodal train speeds have fallen to multi-year lows across the 'Big Four' US Class I railroads.[2]

Independent rail analyst Rick Paterson recently noted that while railroads are built to handle anticipated, steady increases in volume, sudden demand shocks inherently degrade velocity. For BNSF and Union Pacific, average intermodal speeds have dropped to a 10-month low. Norfolk Southern is hovering near a 20-month low, and CSX has seen its intermodal speeds fall to a seven-year low.[1]

To understand why volume is the natural enemy of speed in railroading, it helps to look at the mechanics of an intermodal terminal. Unlike bulk commodities like coal or grain, which are poured into specialized cars, intermodal containers must be individually lifted by massive cranes from truck chassis onto flatcars.

When a terminal receives a 10% or 15% unexpected surge in containers, the physical space to store them temporarily—known as the footprint—fills up. Cranes have to work longer to load and unload trains that are built longer to accommodate the extra freight. This increases 'terminal dwell time,' which is the amount of time a train sits idle before it is cleared to move onto the mainline.[2]

Once on the mainline, heavier and more frequent trains create congestion at switching yards and passing sidings. Bill Stephens, an editor at Trains Magazine, aptly described the phenomenon as a 'rush hour effect,' noting that the slowdown is a broad-based reality affecting both Eastern and Western rail networks equally.

The catalyst for this sudden migration of freight to the rails is rooted in the volatility of the over-the-road trucking market. Earlier in the year, severe weather events and tightening latent capacity triggered the sharpest short-term trucking spot rate spike in more than three years.

As dry-van and temperature-controlled trucking rates climbed, shippers scrambled to protect their margins. Because rail transport is highly fuel-efficient—a single freight train can move a ton of freight nearly 500 miles on a single gallon of fuel—it serves as a vital pressure valve when highway costs become prohibitive.

Furthermore, the maritime shipping industry is experiencing an unusually strong and early peak season. Importers are pulling forward their orders from Asia to avoid potential geopolitical disruptions and labor strikes at ports later in the year. This has flooded West Coast ports with containers that need to be moved inland, predominantly via rail.[1]

The challenge for the Class I railroads is to execute a 'bend-but-don't-break' strategy. They must absorb the lucrative volume without letting service degrade to the point where shippers abandon the network. BNSF successfully managed a similar domestic intermodal surge in late 2023, pulling off a rapid recovery that the broader industry is now attempting to replicate.[1]

To restore fluidity, railroads are aggressively repositioning assets and accelerating hiring. CSX, for example, recently posted notices that it is hiring conductors at 40 different locations across its network. Norfolk Southern has also acknowledged crew shortages in specific regions and is actively recruiting to boost its train and engine ranks at roughly half of its terminals.[1]

The critical variable in the coming weeks will be crew availability. Under federal regulations, train crews can only operate for a maximum number of hours before they must be relieved. When trains move slower due to congestion, crews often 'time out' before reaching their destination, requiring an unplanned 'recrew' to take over the train.

Analysts warn that if unplanned intermodal recrews begin to siphon off the personnel needed to run the railroads' complex merchandise networks—which handle individual carloads of chemicals, metals, and forest products—the congestion could metastasize beyond the intermodal sector.[1]

For now, the broader carload network remains relatively stable. Shipments of metallic ores and metals are up over 10%, and forest products have gained 9%, indicating that the industrial economy is still humming despite the localized friction in container traffic.[1]

Ultimately, this stress test represents a massive opportunity for the rail industry. If the Class I carriers can stabilize their speeds and maintain reliable on-time performance through the summer, they stand to permanently capture a larger share of the freight market from the trucking sector. If they fail, the volume will likely flow back to the highways as soon as truck rates normalize.[1]