RGN, step deck or flatbed: picking the deck before you measure twice

Notes from the yard — published September 3, 2026 by the dispatch desk at Long Road Transportation.

Start from the height you are allowed

Washington's statutory height limit is 14 feet, but almost every multi-state route is planned to 13 feet 6 inches, because that is what the neighbouring states and the low clearances assume. Take 13'6" as the working ceiling and the trailer choice falls out of the subtraction.

• Flatbed — deck sits around 5 feet off the ground, leaving roughly 8'6" of cargo height. Loads from any side, by crane or forklift. Steel, lumber, pipe, palletised machinery.
• Step deck — the lower deck drops to roughly 36 to 42 inches, so cargo can run about 10 feet tall. Loads by crane, forklift or ramps off the back.
• RGN — the gooseneck detaches at the front so a machine drives on from ground level into the well. Cargo of about 11'6" stays legal, and the trailer carries well past 80,000 pounds gross with the right axle configuration.

Height is the constraint. Loading method is the tie-breaker

If two trailers both clear on height, the question becomes how the cargo gets on. A step deck needs a crane, a forklift big enough for the piece, or ramps and a machine that can climb them. An RGN needs none of that: drop the neck, drive the machine into the well, reconnect.

That matters on job sites with no lifting equipment, and it matters on the return trip when a customer assumed a crane would be waiting and it is not. We have moved plenty of loads onto an RGN purely because the receiving end had nothing to lift with.

An RGN does not make everything legal

It is the lowest practical starting point, not a permit waiver. A machine that is 12 feet tall on the ground is still oversize in the well of an RGN, and it still needs a permit, a route survey and possibly escorts. What the RGN buys is the difference between a routine permit and a route that has to dodge every overpass in the corridor.

Width and length work the same way. Once a load passes 8'6" wide it is permitted regardless of which deck it sits on, and the escort rules turn on the dimensions, not the trailer. That side of it is covered in oversize permits and pilot cars in Washington.

What to send when you ask for a rate

Four numbers and a photo settle the trailer choice in one exchange instead of three:

• Length, width and height of the piece as it will sit — not the crated dimensions from the catalogue.
• Weight, and where the centre of gravity is if it is not obvious.
• How it will be loaded and unloaded, and whether there is lifting equipment at either end.
• Pickup and delivery addresses, so the route can be checked for clearances before anything is promised.

We own the decks

Flatbeds, step decks and RGNs are our own equipment, dispatched out of Kent and Tacoma alongside the container fleet. That is the reason an out-of-gauge box off the Port of Tacoma and the machinery it is going to sit next to can move on the same day under one dispatcher.

Questions we get asked

How tall can cargo be on a step deck?

Roughly 10 feet, working from a lower deck at 36 to 42 inches against a 13'6" planning ceiling. An RGN buys about another 18 inches.

When is an RGN worth the extra cost over a step deck?

When the piece is too tall for a step deck, too heavy for its axle rating, or when neither end of the move has lifting equipment and the machine has to drive on.

Do you provide the permits?

Yes. Permits, routing and escorts are arranged as part of the move, not left to the shipper.

Read next

• Oversize in Washington: what triggers a permit, and what triggers escorts
• Liftgate, residential and limited access: what the delivery site costs you

Long Road Transportation is an asset-based carrier operating its own trucks, chassis and heavy-haul equipment out of Kent and Tacoma, Washington. USDOT 3388302, MC 113242, SCAC LRDP.