When do you actually need an oversize permit?

The federal baseline

On the National Network, these are the figures everything else is measured against. Go over any single one of them and you are oversize or overweight:

Width is the one that almost never moves: all 48 contiguous states set the legal limit at 8’6". Height is where states genuinely differ, and it is the limit most often got wrong.

Where height differs — and it does

“Thirteen six” is the number everyone quotes. It is correct in 26 states. In the other 22 you can run taller without a permit:

20 states allow 14'0". Only Colorado and Nebraska go to 14'6" — the highest legal height in the country. None of this helps if one state on your route is stricter: the permit requirement is per state, and the tightest state on the route governs whether you need one there.

The divisible-load rule that gets drivers ticketed

This is the one that catches people. A permit is for a non-divisible load — something that cannot be taken apart without destroying its value or the thing itself. A transformer, a crane boom, a prefabricated section.

Pallets, lumber, aggregate, containers of loose goods and anything you could split across two trailers are divisible. States will generally not issue an oversize permit for them at all, and running one over the limit without a permit is an overweight citation, not a paperwork problem.

• Non-divisible: one piece, cannot be reduced without ruining it. Permittable.
• Divisible: could be split into legal loads. Usually not permittable.
• Some states have narrow exceptions — for baled commodities, certain agricultural hauls, or emergency movements. They are specific and worth checking before you rely on one.

Legal limits by state

Every contiguous state, with the limits its own rules set. Anything over these figures needs a permit in that state.

Questions