A load becomes over dimensional the moment it passes the envelope a state allows without asking. There is no single national number to memorize, because width is federal on some roads, height is entirely a state matter, and escorts are written state by state in language that rarely matches the state next door. The thresholds below come from a federal publication and three state sources, all read on 2026-07-29.
Every figure on this page is a published limit with its source printed beside it. No prices appear, because permit and escort charges are set per state and per trip.
Start with what is federal. The FHWA publication on size regulations puts the width limit at 102 inches on the National Network and reasonable access routes, with Hawaii allowed 108 inches, and states the point that surprises people: there is no federal vehicle height requirement for commercial motor vehicles, so states may set their own, and most sit between 13 feet 6 inches and 14 feet. Length works the other way around, as a floor states must allow rather than a ceiling: 48 feet for a semitrailer in a tractor-semitrailer combination and 28 feet for each trailer in a twin combination.
| Dimension | Texas legal limit | Where people trip over it |
|---|---|---|
| Width | 8 ft 6 in for vehicles and loads other than passenger vehicles | The same 102 inches the trailer itself is built to, so cargo overhang goes straight past it |
| Height | 14 ft, all vehicles | Measured from the road, so a tall crate on a raised deck arrives at the limit sooner than expected |
| Length, single motor vehicle | 45 ft | Applies to the vehicle itself, not to a combination |
| Length, semitrailer in a two-vehicle combination | 59 ft | Rear overhang is what usually pushes a load past this, not the trailer |
| Length, two-vehicle combination other than a truck-tractor combination | 65 ft | Straight truck and trailer setups reach it earlier than a tractor and semitrailer |
| Gross weight | 80,000 lb maximum | Overweight is permitted separately from oversize, and a load can be both |
Texas is one state of fifty. The value of reading its page is not that the figures transfer, it is that they show the shape of every state's table: a width, a height, two or three length figures depending on how the vehicles are coupled, and a weight ceiling with its own permit process.
Permits and escorts are separate decisions. A load an inch over legal needs paper; it does not necessarily need a pilot car. Where the escort line falls is written by each state, and reading two of them side by side shows how far apart they can be.
| Condition | Washington | Minnesota |
|---|---|---|
| Width on a two-lane or undivided road | Exceeds 11 feet: two pilot or escort vehicles on two-lane highways | Exceeds 15 feet at the bottom or 16 feet at the top: certified front and rear escorts on undivided roadways |
| Width on a multilane road | Exceeds 14 feet: one escort at the rear on multilane highways. Exceeds 20 feet: two on multilane undivided highways | Exceeds 15 feet at the bottom or 16 feet at the top: a certified rear escort on multilane divided roadways |
| Height | Exceeds 14 feet 6 inches: one pilot or escort vehicle with a height measuring device, meaning a pole car | Not stated on the escort page; the state patrol is named as the contact for further escort detail |
| Length | Trailer exceeding 105 feet, or rear overhang past one third of trailer length, takes a rear escort on two-lane highways; a trailer past 125 feet takes one on multilane | Exceeds 110 feet: rear escort on multilane divided roads, front and rear on undivided. Exceeds 150 feet: certified front and rear escorts |
| Crossing the center line | Front overhang past 20 feet takes a front escort on all two-lane highways | Any part of the load extending beyond the left of the center line on an undivided roadway takes a certified licensed lead peace officer plus front and rear escorts |
Take a twelve-foot-wide machine as the example. On a Washington two-lane it is already into two pilot vehicles. Under Minnesota's width triggers it is below the line on either road type, and the escort conversation there starts at fifteen feet. A route that clips both states therefore carries the Washington cost for the Washington miles, which is why quotes for the same freight change when the routing changes. MnDOT also reserves the right to require additional escorts where it judges them necessary to protect public safety or the road structures.
Above 14 feet 6 inches Washington requires a pilot vehicle carrying a height measuring device. It runs ahead with a pole set to the load height, and a bridge or a low span that clips it is one that would otherwise have hit your freight.
The same Washington regulation tells operators to prerun the route, if necessary, to verify acceptable clearances. On a tall load through unfamiliar country that is not a formality, it is the difference between a survey day and a stuck truck.
Signal arms, sign gantries, canopies over fuel islands and low utility lines all live in the same band as a tall load, and some of them are on the last mile rather than the highway.
Height is the dimension that punishes guesswork hardest, because a bridge strike is a police matter and a repair bill rather than a fine. Measure from the ground with the load sitting on the trailer that will actually haul it, and take the tallest point rather than the average.
No dollar amounts appear here. Permit fees are set by each state for each trip, escort firms price by the mile or by the day, and a page that printed numbers today would be quietly wrong within a season. The structure of the cost is stable enough to plan against, and it looks like this.
| Added item | How it is charged |
|---|---|
| Permits | One per state crossed, per trip, at that state's own schedule. A five-state run is five applications, not one |
| Pilot or escort vehicles | Each is a vehicle and a certified driver moving with the load, billed by distance or by day, plus their travel to reach the pickup |
| Lead police officer | Where a state requires one, as Minnesota does when a load crosses the center line on an undivided road, the agency sets the charge and the availability |
| Route survey | A day or more of driving the route before the load moves, and any utility or signal work that survey turns up |
| Time | Permitted loads generally travel in daylight, sit out weekend and holiday curfews in some states, and take longer routes to avoid a restriction. The truck is paid for every one of those days |
The practical consequence is that the cheapest routing for an over dimensional load is often not the shortest one. An extra hundred miles that stays on multilane divided highway can drop an escort requirement, and that trade is worth putting in front of whoever quotes the move.
Height is the distance from the pavement to the highest point of the load. Deck height and dunnage are part of the total, and so is a tarp stretched over the top.
Handles, brackets, protruding shafts and any part of the packaging count. Minnesota's rule shows why the detail matters, since it names a width at the bottom and a different one at the top.
Front and rear overhang are measured from the vehicle, not from the freight, and several escort triggers are written against overhang rather than total length.
Write the four numbers down with the weight, then hand the same four to every party who asks. Most of the expensive surprises in permitted freight trace back to a load that was measured on the shop floor and grew when it went onto a trailer.
SMKlog sells US domestic parcel labels directly and routes anything past parcel to a person. Over dimensional moves are the far end of that: they need a carrier with the right trailer, permits pulled in each state on the route, and escorts booked to match. We do not pull permits or run pilot cars ourselves. Send the dimensions, the weight and both ends of the lane through the review form and a person works out what the move takes before quoting it.
Sources read 2026-07-29: ops.fhwa.dot.gov federal size regulations for commercial motor vehicles, txdmv.gov Texas size and weight limits, WAC 468-38-100, dot.state.mn.us escort requirements.
Any load that passes the legal envelope of a state it drives through. The FHWA describes the federal width limit as 102 inches on the National Network and reasonable access routes, with Hawaii at 108 inches, but there is no federal height requirement at all, so each state sets its own and most land between 13 feet 6 inches and 14 feet.
No, and the two thresholds are far apart. A permit starts at a few inches over legal, while escort triggers sit much higher and differ by state and by road type. Washington calls for two pilot vehicles on a two-lane highway once a load exceeds 11 feet in width, while Minnesota's rear escort trigger on a multilane divided road is 15 feet measured at the bottom, or 16 feet at the top.
Driving the route before the load does, to confirm the clearances are really there. Washington's rule tells operators to prerun the route, if necessary, to verify acceptable clearances, and above 14 feet 6 inches of height it requires a pilot vehicle carrying a height measuring pole.
No dollar figures appear on this page because permit fees are set by each state for each trip and escort companies price by the mile or by the day. What you can plan for is the shape of the cost: a permit in every state crossed, an extra vehicle and driver for each escort, a lead officer where a state requires one, and a slower trip because permitted loads generally move in daylight and avoid holidays.
Measure it standing on the trailer it will travel on, not on your floor. Height is taken from the road surface with the tarps and any dunnage already in place, width at the widest point including anything that sticks out, and overhang from the rear of the trailer rather than from the freight.