The short version: a load is non-divisible if splitting it would compromise the vehicle's intended use, destroy the value of the load or vehicle, or take more than 8 work hours to dismantle with appropriate equipment — any one of the three is enough, and the applicant carries the burden of proof on the hours. If the load is divisible, there is no permit to price: the answer is to split it. Both federal passages are quoted verbatim below, behind their own citations.
The federal definition, verbatim
23 CFR §658.5, as quoted in the Glossary of Terms, Compilation of Existing State Truck Size and Weight Limit Laws — FHWA, May 2015. Public domain (17 U.S.C. §105).verbatim
"any load or vehicle exceeding applicable length or weight limits, which, if separated into smaller loads or vehicles, would: (1) Compromise the intended use of the vehicle …; (2) Destroy the value of the load or vehicle …; or (3) Require more than 8 work hours to dismantle using appropriate equipment. The applicant for a non-divisible load permit has the burden of proof regarding the number of work hours required to dismantle the load. A State may treat emergency response vehicles, casks designed for the transport of spent nuclear materials, and military vehicles transporting marked military equipment or materiel as non-divisible vehicles or loads."
This is the operative federal definition of what needs an oversize or overweight permit at all, and the 8-work-hour test is the part that decides most real arguments. It is a measurable threshold, not a judgement call, and it is the applicant who has to substantiate it.
And what a divisible load is
Glossary of Terms, Compilation of Existing State Truck Size and Weight Limit Laws — FHWA, May 2015. Public domain.verbatim
"Definitions vary by State: generally, a divisible load is one that can be reduced in size or weight, or that is practically divided in a way that does not diminish value or inhibit its intended purpose."
Note that the federal glossary itself says the definition varies by state. The non-divisible test above is the federal floor; a state can and does add its own products on top of it.
Why this decides the whole quote
The non-divisible question comes before every other question on this site. If the load is divisible, the answer is not "how much is the permit" — it is "split the load", and no permit is available at all on the federal test. If it is non-divisible, everything else follows: which state permits, at what fee, with what escorts, under what restrictions.
- Is it over a legal limit? — the dimension side.
- Is it over on weight? — the axle-group side, which no table can answer.
- What does the permit cost?
- Does it need a pilot car? — usually the larger number.
Questions
What makes a load non-divisible?
Federal law gives a three-part test: separating the load into smaller loads would compromise the intended use of the vehicle, destroy the value of the load or vehicle, or require more than 8 work hours to dismantle using appropriate equipment. Meeting any one of the three is enough.
Who has to prove it?
The applicant. The federal definition puts the burden of proof about the number of work hours on the person applying for the permit, not on the agency.
Does a divisible load ever get a permit?
Some states issue overweight permits for specific divisible commodities under their own statutes, but that is a state product and it is not what the federal non-divisible definition covers. The federal definition is what decides whether a load is eligible for an oversize/overweight permit on the Interstate at all.
What about emergency vehicles and military equipment?
Federal law lets a state treat emergency response vehicles, casks designed for the transport of spent nuclear materials, and military vehicles transporting marked military equipment or materiel as non-divisible — it permits that treatment rather than requiring it.