Drayage · July 9, 2026
A heavy container is legal to haul — but only with the right axle setup, route and permit. Here's how it works.
Ocean containers don't care about U.S. road law. A 20-footer packed with something dense — tile, stone, machinery, liquids — can easily put you over legal highway weight once it's on a chassis. Move it wrong and it's a fine, a stuck load, or an unsafe truck. Move it right and it's just another container.
Federal law caps you at 80,000 lbs gross without a permit, with limits per axle (roughly 12,000 on the steers, 34,000 on each tandem). Washington follows those, plus bridge-law spacing rules. The cargo weight might be legal in the box but illegal on the truck if it's on the wrong chassis or the axles aren't spread to carry it.
Go over 80,000 gross or over an axle limit and you're into overweight-permit territory — a state permit, sometimes a specific routing, and often a tri-axle or spread-axle chassis to keep each axle legal. The Ports of Seattle and Tacoma see a lot of heavy freight, so this is routine work, but it has to be set up before the truck shows up, not after.
We flag heavy containers before dispatch, match them to the right chassis (tri-axle or spread where needed), pull the permit and set the route, and make sure the axle weights are legal — not just the gross. Because we run the drayage ourselves, the weight gets checked against the equipment before the truck rolls, not discovered at the scale.
Federally, 80,000 lbs gross without a permit, with axle limits around 12,000 lbs on the steer and 34,000 lbs per tandem. Washington follows these plus bridge-spacing rules. Over any of them and you need an overweight permit.
When the loaded truck exceeds 80,000 lbs gross or any axle limit. That usually also means a tri-axle or spread-axle chassis to keep each axle legal, and sometimes a specified route.
The cargo can be within limits in the box but still overload an axle if it's on the wrong chassis or the axles aren't spread to distribute it. Matching the container to the right chassis is the fix.
Yes — heavy freight is routine at these ports. We match the box to the right chassis, pull the permit and set a legal route before dispatch.