What Is a Nondivisible Load? The 23 CFR 658.5 Definition in Plain English

A nondivisible load (also called an indivisible or non-divisible load) is a load or vehicle over legal length or weight limits that cannot be split into smaller loads without ruining what it does, destroying its value, or taking more than 8 work-hours to take apart. That is the federal definition in 23 CFR 658.5, and it is what lets a state issue an overweight permit for the Interstate System.

If your load can be split up, the federal rule expects it to be split, not permitted. This guide quotes the regulation, walks through the three tests in plain English, lists the examples the Federal Highway Administration (FHWA) itself gives, and shows how two states word their own definitions. Every source is linked and was checked November 13, 2026.

For other permit vocabulary, see our OS/OW permit terms glossary.

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The federal definition, word for word

The definition sits in 23 CFR 658.5, the definitions section of the federal truck size and weight rules. Paragraph (1) reads:

“As used in this part, nondivisible means any load or vehicle exceeding applicable length or weight limits which, if separated into smaller loads or vehicles, would:
(i) Compromise the intended use of the vehicle, i.e., make it unable to perform the function for which it was intended;
(ii) Destroy the value of the load or vehicle, i.e., make it unusable for its intended purpose; or
(iii) Require more than 8 workhours to dismantle using appropriate equipment. The applicant for a nondivisible load permit has the burden of proof as to the number of workhours required to dismantle the load.”

Paragraph (2) adds a short list of things a state may treat as nondivisible: emergency response vehicles (including salt, sand or chemical spreaders, with or without a plow or blade, used on roads that are or may become slick or icy), casks designed to carry spent nuclear materials, and military vehicles carrying marked military equipment or materiel (23 CFR 658.5).

Two things to notice. The three tests end in “or”, so the regulation lists them as alternatives: meeting one is enough. And the person asking for the permit carries the burden of proof on the work-hours test, not the state.

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The three tests in plain English

1. It would stop working. Taking it apart would leave the vehicle unable to do the job it was built for.
2. It would be ruined. Splitting it would destroy the value of the load or vehicle, so it could not be used for its purpose.
3. It takes too long to take apart. Dismantling it with the right equipment would take more than 8 work-hours.

The FHWA size and weight questions and answers clear up how the 8-hour test is counted:

• Work-hours are person-hours. FHWA says it means “8 person hours, i.e., 8 hours for one person, 4 hours apiece for two persons, or 2 hours apiece for 4 persons.”
• Only taking it apart counts. Asked whether reassembly time is included, FHWA answers: “No. It includes only disassembly time.”
• No partial teardown. If a load cannot be dismantled in 8 hours, it is nondivisible and does not have to be broken down as far as possible in 8 hours. But FHWA adds that if parts are removed to make an overweight load easier to haul, “they cannot be loaded on the same vehicle.”

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Divisible or nondivisible? Examples from official text

These examples come straight from the regulation and FHWA’s own answers. They are not guesses about a particular load.

The pattern: if the extra weight is something you could put on another truck (water, pipe, a blade you already took off), it is divisible. If splitting the item would wreck it or stop it working, or the teardown runs past 8 person-hours, it fits the definition.

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Why it matters: what a nondivisible permit allows

On the Interstate System, the federal weight limits are 20,000 pounds on a single axle, 34,000 pounds on a tandem and 80,000 pounds gross, or less where the Bridge Formula says so (23 CFR 658.17(b)–23 CFR 658.17(e)). Under 23 CFR 658.17(h), “States may issue special permits without regard to the axle, gross, or Federal Bridge Formula requirements for nondivisible vehicles or loads.”

FHWA describes the statute behind it the same way: under 23 U.S.C. 127(a) the 80,000-pound gross limit applies “except for those vehicles and loads which cannot be easily dismantled or divided, and have been issued permits in accordance with applicable State laws” (FHWA’s FAST Act truck size and weight page). See our guide to reading overweight permit axle weights for how those allowed weights show up on a permit.

• Where the federal definition applies. For overweight permits, on the Interstate System and the highways that give reasonable access to and from it. For combinations with two or more cargo-carrying units under the federal length freeze, on the highways in Appendix C to 23 CFR 658 (FHWA Q&A).
• Other roads. FHWA says the federal definition “applies only on the Interstate System” for weight (FHWA Q&A). Off the Interstate, the state’s own law sets the test, and state wording can differ (next section).
• Width is separate. The federal definition talks about length and weight limits. Width has its own rule: 23 CFR 658.15(c) lets a state grant special use permits for vehicles over 102 inches wide.
• The burden is on you. On the 8-hour test, the permit applicant has to prove the work-hours (23 CFR 658.5).

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How states word it: two verified examples

States issue the permits, and many write their own definition. Two examples, read on each state’s own site and checked November 13, 2026:

• Florida. FDOT’s rule says permits for overweight and overdimensional vehicles and loads “are intended for a single item load which cannot reasonably be dismantled or disassembled and which cannot reasonably be shipped by rail, water, or air,” and that all reasonable steps must be taken to reduce the load to legal limits (Rule 14-26.00411(2), F.A.C.). The rail, water or air factor does not appear in the federal definition. More in our Florida oversize permit guide.
• Nebraska. Nebraska defines a non-divisible load as “a vehicle or load that cannot be dismantled, disassembled, or reduced in size or weight without great difficulty to meet the statutory size and/or weight limits” (408 NAC 3-001.16). It uses “without great difficulty” instead of an 8-hour count, and covers size as well as weight. A special permit may be issued for a non-divisible load over the legal weight, height, length or width limits (408 NAC 3-002.03). More in our Nebraska oversize permit guide.

When the state wording and the federal wording differ, the state that issues your permit decides what it will permit, within the federal limits on its Interstate routes. Ask the issuing permit office if you are unsure whether your load qualifies. Crossing several states? Each one applies its own rules: see multi-state oversize permit trips.

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What this means when you read your permit

A permit is issued for the load described on it. Before you roll:

• Match the load line. Check that the load description, dimensions and weights on the permit match what is actually on the deck.
• Don’t top off. Extra items that could ride on another truck make the load divisible. FHWA is plain that parts removed to make an overweight load easier to haul “cannot be loaded on the same vehicle” (FHWA Q&A).
• Read every condition. Routes, times, axle weights and pilot car requirements are set on the permit and its attachments. If anything here seems to disagree with your permit, the permit face wins.

Our guide on how to read an oversize load permit walks through each part of the document. To see everything on one card, drop the issued permit PDF into the JaloPermit decoder: it lays out the route, pilot cars, curfews, dimensions and limits so you can check them against the original.

JaloPermit, which publishes this guide, is a reading aid for issued permit PDFs. It is not a permit-filing service and it does not decide whether a load is nondivisible. Guests get three free decodes a day with no account and no card. Logged-in users get 10 free decodes a day. After those free decodes, each one is $3.50. There is no subscription.

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FAQs