Oversize and overweight permits
If a load is too wide, too tall, too long or too heavy for the legal limits, every state on the route has to approve the move first. Here's how the federal limits work, what states control, and how permits, escorts and travel times fit together.
Key takeaways
- Federal law sets 102 inches of width on the National Network and 80,000 lb gross, 20,000 lb per single axle and 34,000 lb per tandem on the Interstate System, plus the bridge formula.
- There is no federal height limit. FHWA says state height limits range from 13.6 to 14.6 feet.
- The federal government doesn't issue oversize or overweight permits. Each state issues its own, so a multi-state move needs a permit from every state.
- Escorts, flags, signs, lights and allowed travel times are set by each state and printed on the permit. Read every permit before you roll.
Read this first
This page is general information, not legal advice. Size and weight rules change and differ by state, road and load. The permit itself, and the issuing state's rules, are what count. Always confirm with each state's permit office before you accept or move a load.
Oversize means wider, taller or longer than the legal limit. Overweight means heavier than the legal gross or axle weight. A load can be both. Permits are generally for nondivisible loads: under 23 CFR 658.5, a load that, if split into smaller loads, would lose its intended use, be destroyed in value, or take more than 8 work hours to take apart with the right equipment. The person asking for the permit has to prove the work hours.
The federal limits
Federal rules in 23 CFR Part 658 set the floor and ceiling states must follow on certain highways:
| Limit | Federal rule | Where it applies |
|---|---|---|
| Width | 102 inches. States may not set more or less (Hawaii keeps 108 inches). Safety devices like mirrors don't count. | National Network (658.15) |
| Gross weight | 80,000 lb, or less if the bridge formula requires it | Interstate System and reasonable access (658.17) |
| Single axle | 20,000 lb | Interstate System (658.17) |
| Tandem axle | 34,000 lb | Interstate System (658.17) |
| Semitrailer length | States may not set less than 48 feet in a tractor-semitrailer, or less than 28 feet per trailer in a twin | National Network (658.13) |
| Height | No federal limit | Set by each state |
Bridge formula. To protect bridges, the weight on any group of two or more consecutive axles can't go over W = 500 × (LN/(N−1) + 12N + 36), where W is the weight in pounds (to the nearest 500), L is the distance in feet between the outer axles of the group, and N is the number of axles in the group. Two consecutive tandems may carry 34,000 lb each if the first and last axles are at least 36 feet apart. Check your axle spacing with the axle weight and bridge formula calculator.
These weights include all tolerances, except a scale allowance of up to 5% for portable scales. Trucks with a qualifying idle reduction unit may get up to 400 lb extra, with proof of its weight on board.
What states control
- Height. There's no federal height limit. FHWA's overview says state limits range from 13.6 to 14.6 feet. Texas, for example, allows 14 feet without a permit.
- Permits. FHWA says plainly that the federal government doesn't issue oversize or overweight permits. That's a state option. States may issue permits for nondivisible loads without regard to the federal axle, gross or bridge formula limits (658.17(h)), and may grant special permits for loads wider than 102 inches (658.15(c)).
- Routes. A permit usually comes with an approved route that avoids low clearances, weak bridges, load-restricted roads and work zones. Stay on it.
FHWA keeps a list of every state's permit office phone number on its oversize/overweight permit page. Some official state permit sites:
- Texas: TxDMV issues permits through the Texas Permitting & Routing Optimization System (TxPROS), or call (800) 299-1700.
- California: Caltrans Transportation Permits takes single-trip, annual and repetitive permit applications online.
- Minnesota: MnDOT issues annual, seasonal and single-trip permits online and posts its travel restrictions, seasonal load limits, holiday schedule and rush hour zones.
Example: Texas numbers from TxDMV
Texas publishes its limits on the TxDMV site. These are examples only. Other states' numbers are different.
| Item | Texas rule |
|---|---|
| Legal without a permit | 8'6" wide, 14' high, 80,000 lb gross, 20,000 lb single axle, 34,000 lb tandem (plus the Texas permissible weight table) |
| Single-trip permit | For nondivisible loads up to 254,300 lb, one move from a set origin to a set destination, during the times on the permit. Base permit fee $60, plus a highway maintenance fee over 80,000 lb. |
| Super Heavy permit | Over 254,300 lb gross, over the maximum permit axle weights, or over 200,000 lb with less than 95 feet of axle spacing |
| Route inspection certification needed | Over 20' wide, 18'11" high or 125' long |
| Permit check | TxDMV checks your USDOT number in FMCSA's system for out-of-service orders before issuing |
Texas escorts (most permit types):
- Width over 14' to 16': 1 front escort on two-lane roads, 1 rear on multi-lane roads. Over 16': front and rear on all roads.
- Height over 17': 1 front escort with a height pole. Over 18': front and rear.
- Length over 110' to 125': 1 front on two-lane, 1 rear on multi-lane. Over 125': front and rear.
- Front or rear overhang over 20': 1 rear escort.
- TxDMV may also require a law enforcement escort.
Texas holidays: loads over 14' wide, 16' high or 110' long may not move on Memorial Day, Independence Day, Labor Day, Thanksgiving Day, Christmas Day or New Year's Day unless TxDMV grants an exception.
Flags, signs, lights and escort vehicles
Marking rules are set by each state, and your permit lists the conditions for your move. As an example, Texas requires:
- Flags: 12-inch red flags on the ends of a load that sticks out past the sides, or more than 4 feet past the rear.
- Lights: for a load that extends more than 4 feet past the rear, red lamps and reflectors on the end of the load and red lamps on each side.
- Escort vehicle signs: "OVERSIZE LOAD" or "WIDE LOAD" in black on yellow, 5 to 7 feet long and 12 to 18 inches high, on the roof or front and rear, used only while escorting.
- Escort vehicle lights and radio: flashing or rotating amber lights visible from all sides, and two-way radio contact with the load and other escorts.
- Escort duties: warn traffic when the load must cross the center line, swing into opposing lanes on a turn, slow down under a low structure or over a bridge, or create unusual traffic flow.
Other states' sizes, colors and trigger points differ. Check each state's rules for the whole route.
Travel time restrictions
- Times on the permit. A permit says when you may move. Texas single-trip permits, for example, may only be used during the times specified on the permit.
- Holidays. States such as Texas and Minnesota restrict oversize moves on holidays. Texas lists its restricted dates on the TxDMV holiday page, and MnDOT publishes a holiday travel schedule.
- Rush hours. Some states limit moves during peak traffic. MnDOT, for example, publishes rush hour zones.
- Seasons. Some states post seasonal load limits, such as MnDOT in Minnesota. Your permit and the state's site have the details.
- Hours of service still apply. Waiting for daylight, escorts or a curfew to end eats your 14-hour window. Plan with the HOS calculator.
Before you accept an oversize load
- Get the exact dimensions and weight of the load and your truck and trailer together. Permits are based on the loaded combination.
- Ask who is buying the permits and escorts, and get it on the rate confirmation.
- Get a copy of every state's permit before you leave and keep them in the cab. Check the names, USDOT number, truck and trailer, dimensions, route and dates.
- Ask about pickup and delivery hours. If the permit limits your travel times, make sure the appointments fit them.
- Check the route for low clearances and weight-restricted bridges, even if a permit service drew it.
- Secure the load to the federal cargo securement rules. See the cargo securement guide.
Fleetorica dispatches step deck and flatbed trucks. We flag permit and escort needs before you accept a load. Permits are issued by each state to the carrier, and Fleetorica is not a broker or a carrier.
Tall and heavy machinery usually rides on a lower deck. See how we dispatch lowboy/RGN, double drop and Conestoga trailers.
- 23 CFR 658.5: Definitions (nondivisible load or vehicle)
- 23 CFR 658.13: Length
- 23 CFR 658.15: Width
- 23 CFR 658.17: Weight
- FHWA: Federal size regulations for commercial motor vehicles
- FHWA: Oversize/overweight load permits and state permit contacts
- TxDMV: Oversize/overweight permits
- TxDMV: Texas size/weight limits
- TxDMV: General single-trip permits
- TxDMV: Escort and equipment requirements
- TxDMV: Holiday hours and movement restrictions
- TxDMV: Texas Permitting & Routing Optimization System (TxPROS)
- Caltrans: Transportation permits (oversize/overweight vehicles)
- MnDOT: Minnesota oversize/overweight permits
This page is general information, not legal or tax advice. Rules change; confirm with FMCSA, the IRS or your state before you file.
Questions carriers ask
Is there a federal height limit for trucks?
No. Federal rules set width and weight limits but no height limit. FHWA says state height limits range from 13.6 to 14.6 feet, so check each state on your route.
Can I get one permit for a trip through several states?
The federal government doesn't issue oversize or overweight permits. Each state issues its own, so you need a permit from every state you'll cross, each with its own route and conditions.
What is a nondivisible load?
Under 23 CFR 658.5, it's a load that, if split up, would lose its intended use, lose its value, or take more than 8 work hours to take apart with the right equipment. States can issue overweight permits for these loads beyond the federal axle, gross and bridge formula limits.
When do I need an escort in Texas?
For most permit types, TxDMV requires escorts above certain sizes: for example, width over 14 feet, height over 17 feet, length over 110 feet, or overhang over 20 feet. The number and position depend on the size and the type of road. Other states have their own rules.