A load too wide, too tall, too long or too heavy for a standard truck does not get one permit that covers the country. The Federal Highway Administration says so plainly: the federal government does not issue oversize or overweight permits at all. That is a state function, and every state runs its own system, with its own thresholds for when an escort car becomes mandatory. Moving a genuinely large load across several states means dealing with several separate permit offices, not one.
The federal baseline, and how little of it is actually federal
Federal rules set a floor for a small number of dimensions. The Surface Transportation Assistance Act fixed 8 feet 6 inches as the standard legal width on the National Network of qualifying highways, and a related rule sets minimum length allowances for semitrailer combinations, 48 feet for a single semitrailer and 28 feet where a second trailer is involved, that states cannot restrict further on that network. There is no federal maximum height at all; 13 feet 6 inches is common because many states independently chose it, not because a federal rule requires it.
On weight, the federal maximum for unpermitted travel on the Interstate system is 80,000 pounds gross vehicle weight, governed by the federal bridge formula, which caps the weight a given group of axles can carry based on their spacing. That figure is a ceiling for ordinary traffic, not an absolute cap: overweight permits routinely authorise well above it, and as the superload examples below show, some states' heavy-haul thresholds start at more than that figure.
Escort requirements genuinely differ state to state, with real numbers to prove it
This is the point most worth internalising if you move heavy freight across state lines: the width at which a first escort becomes mandatory is not a fixed industry number. Checked directly against each state's own published requirements:
- Texas requires one escort for widths over 14 feet up to 16 feet, and two escorts, front and rear, above 16 feet on any road. A height over 17 feet requires a front escort carrying a nonconductive height pole; over 18 feet requires front and rear. Length over 110 feet up to 125 feet requires one escort, and beyond 125 feet requires two.
- Ohio requires a single lead escort once width exceeds 13 feet, a lead escort equipped with a height-sensing device once height exceeds 14 feet, and a rear escort once length exceeds 90 feet.
Those two states alone show the first-escort width trigger moving by a full foot, 13 feet in Ohio versus 14 feet in Texas. Widely circulated generic tables claiming a single universal threshold, commonly "one escort over 12 feet," do not match either state's own published rule, and should be treated with suspicion. Confirm the actual threshold against the specific state's transportation or public safety department before you plan a route, not against a generic comparison chart.
No national permit, but one real regional exception
Confirmed directly from FHWA: there is no consolidated system, and each state's permit office has to be approached individually. There is one genuine multi-state mechanism worth knowing about, the Western Regional Permit, covering roughly fourteen western states, under which a carrier can apply through a single member state and receive authority covering the oversize legs of a trip within that group, for loads within the arrangement's dimension limits. It is real and it is codified in at least one member state's own administrative code, but it is regional and dimension-limited. It does not remove the need for separate permits in every state outside that group, and a genuinely coast-to-coast heavy haul still means an application to nearly every state the route crosses.
What a pilot car actually does
An escort vehicle's job, confirmed consistently across state requirements, is to warn other road users and coordinate with the driver of the oversize load: an "OVERSIZE LOAD" or "WIDE LOAD" banner, amber warning lights visible from a meaningful distance, typically 500 feet or more, and two-way radio communication with the truck. Some states restrict what vehicle class can even serve as an escort, Ohio bars sports cars, convertibles and novelty vehicles and requires a sedan, wagon, van or pickup rated at no more than one ton.
A high pole car is a distinct thing, used specifically for overheight loads. Rather than only warning other traffic, it carries a pole extended taller than the load itself, made of nonconductive material, to physically test overhead clearance ahead of the move, bridges, signal wires, and low overhead utility lines, before the load itself reaches them. Texas requires this specifically for loads over 17 feet tall, and the underlying nonconductive-pole requirement appears in other states' own equipment codes too. This is not the same equipment as a standard escort, and a standard escort car cannot substitute for it on a load that genuinely needs overhead clearance testing.
Escort driving is not always an unlicensed civilian role. Several states require a certified escort driver to complete a state-approved course before operating a pilot car professionally; Florida's own requirement, for example, is an eight-hour approved course with a written exam and recertification every four years. Exactly which states require certification and which recognise each other's cards is genuinely inconsistent across public sources, so confirm the specific requirement for both the origin and destination state rather than assuming your escort's home-state certification travels everywhere.
When a civilian escort is not enough
Above a certain size, some states require a police escort rather than a civilian pilot car. Indiana defines a superload precisely: a load exceeding 17 feet wide, 15 feet tall, 110 feet long, or 108,000 pounds. Moving one requires obtaining a permit through the state's revenue department and then a separate Superload Agreement Number from the Indiana State Police, which schedules the police escort, typically within 72 hours, and reserves escorts for a load under 200,000 pounds only when road conditions warrant it, but requires one for any load at or above 200,000 pounds where the route crosses a bridge subject to a slowdown. Other states set their superload thresholds at meaningfully different figures, so the exact number that triggers a police escort has to be checked state by state and is not a fixed industry figure.
Route surveys and how much lead time to plan for
For a large enough load, a route survey, a physical inspection of the intended path checking bridge clearances, utility lines and turn radii, is standard rather than optional in several states. Utah's own transportation department states plainly that loads exceeding 17 feet 6 inches in height, 17 feet in width, or 300,000 pounds gross weight are processed only Monday through Friday during business hours and can take up to 14 days for approval, and that bridge clearance review for dual-lane trailers can take a minimum of 14 business days on top of that. A standard permit for an ordinary oversize load in a state with an online system is often issued same day or the next business day. The gap between those two figures is the entire reason to apply early on anything approaching superload dimensions rather than assuming a permit will clear in time for a scheduled pickup.
A recent federal change worth knowing
One genuinely current federal development touches this area, even though permitting itself stays with the states. In December 2025, FMCSA renewed, through June 2030, an exemption from the standard 30-minute rest-break requirement specifically for drivers moving permitted oversize and overweight loads under a satisfactory or unrated safety rating. The reasoning given is directly on point: state and local OS/OW permits often restrict which hours and days a load may legally move, and those windows frequently conflict with when a mandatory break would otherwise fall, sometimes leaving a driver with nowhere legal to park an oversize load for the required rest.
Before you plan a multi-state heavy haul
- Check the actual escort threshold in every state on the route, from that state's own transportation or public safety department, not a generic comparison table.
- Confirm whether the load's dimensions or weight cross a superload threshold anywhere on the route, since that can mean a police escort, a longer approval window, or both.
- Ask whether a route survey is required before you commit to a delivery date, particularly on anything approaching 17 feet in height or width.
- Verify your escort provider's certification is valid in every state you will cross, rather than assuming one state's credential is universally recognised.
Our guides to project cargo and out-of-gauge shipping, breakbulk cargo and truck and trailer types and dimensions cover the equipment side of moving something this size, and US drayage and chassis is worth reading if the load's final leg starts or ends at a port.
A forwarder with genuine multi-state heavy-haul permitting experience is the difference between a load that clears on schedule and one that sits waiting on a permit nobody applied for early enough. You can search more than 29,300 logistics companies by country and service in the CargoLinked directory, or post your shipment and let forwarders with project cargo experience come to you.
Permit thresholds, fees and processes are set independently by each state and change without much notice. Confirm current requirements directly with the transportation or public safety department of every state on your route before relying on any figure here.
