Flatbed & Oversize Freight Shipping: What Shippers Need to Know
Machinery, building materials, and oversized loads need different equipment and planning than standard freight. Here's how flatbed and over-dimensional shipping actually works.
Not every shipment fits in an enclosed trailer. Machinery, structural steel, building materials, and anything too tall, wide, or heavy for a standard dry van needs open-deck equipment — and a different level of planning to move it legally and safely. Here's what shippers need to understand before booking flatbed or oversize freight.
What counts as flatbed freight
Flatbed freight is anything that ships on an open trailer instead of an enclosed van — either because it doesn't need protection from the elements, because it's too large to fit through a van's doors, or because it needs to be loaded from the top or side with a crane or forklift.
Common flatbed freight includes construction materials, steel and metal fabrication, agricultural equipment, machinery, and pipe or lumber. It's a different world from palletized LTL freight: loads are secured with chains, straps, and tarps rather than stacked and shrink-wrapped, and they're loaded and unloaded with equipment on both ends rather than a standard dock.
When freight becomes "oversize"
A load crosses into oversize (also called over-dimensional) territory when it exceeds standard legal limits for width, height, length, or weight on public roads. Exact thresholds vary by state, but general legal limits are around 8.5 feet wide, 13.5 feet tall, and 80,000 lbs gross weight — anything beyond that typically requires permits.
Oversize freight isn't automatically a problem. It's extremely common in construction, energy, and manufacturing. But it does change how the shipment has to be planned:
Permits. Oversize and overweight loads require state permits, and a load crossing multiple states needs a permit in each one. Permit requirements and fees vary significantly by state, so a route through five states can mean five separate permit applications.
Route planning. Standard route mapping doesn't account for bridge weight limits, low overpasses, or road width restrictions. Oversize routes have to be planned around those constraints, which sometimes means a longer route is the only legal one.
Escorts and pilot cars. Loads beyond certain width or length thresholds require pilot car escorts — sometimes one, sometimes a front and rear escort, and in some states a police escort for the widest or heaviest loads. States set their own thresholds for when escorts are required.
Travel restrictions. Many states restrict oversize loads to daylight hours only, and some prohibit travel on weekends or holidays. That affects how transit time gets estimated.
The equipment options
Not all flatbed equipment is the same, and the right choice depends on your load's dimensions:
Standard flatbed — a flat, open trailer sitting at standard deck height, typically used for freight that's oversized in width or length but not height.
Step deck (drop deck) — has a lower deck height than a standard flatbed, which allows taller freight to stay under legal height limits.
Removable gooseneck (RGN) — the front of the trailer detaches and lowers to the ground, allowing wheeled or tracked equipment (like excavators) to be driven directly onto the deck rather than lifted.
Double-drop / lowboy — an even lower deck section in the middle, used for the tallest freight, like large industrial equipment.
Stretch trailers — extendable flatbeds or step decks for freight that's too long for a standard-length trailer, like long structural steel or wind turbine components.
Choosing the wrong equipment means either freight that doesn't fit or a load that comes in overweight/over-height when a lower-deck option would have kept it within legal limits — so accurate measurements matter more here than with almost any other freight type.
What to have ready before you book
Flatbed and oversize freight needs more upfront detail than a standard LTL or dry van quote:
- Exact height, width, length, and weight — measured, not estimated
- Whether the load needs tarping (weather protection) or can ship open
- Loading and unloading method (forklift, crane, drive-on)
- Whether the freight has irregular dimensions that affect how it sits on the trailer
- Origin and destination site conditions — is there room for a longer combination vehicle to maneuver?
Getting these details right the first time avoids the two most common flatbed problems: a truck arriving with the wrong equipment, or a permit application getting kicked back because the dimensions submitted don't match the actual load.
Why this freight benefits from a broker who does it regularly
Flatbed and oversize shipping has more moving parts than standard freight — equipment selection, permitting, route planning, escort coordination — and mistakes in any one of those areas can mean a delayed shipment, a rejected permit, or a fine. A broker who books this freight regularly knows which carriers actually run the equipment you need, how to get permits processed without back-and-forth, and how to plan a route that doesn't hit a bridge restriction three states in.
Route 89 Logistics coordinates flatbed, step deck, RGN, and stretch trailer capacity through our carrier network, along with the permitting and route planning that oversize freight requires. If you've got machinery, building materials, or an over-dimensional load to move, get a quote and we'll tell you exactly what equipment and paperwork it needs.