The Core Distinction:
Oversize means your load or vehicle exceeds legal dimensional limits — height, width, or length. Overweight means you exceed legal weight limits — gross vehicle weight, axle weight, or bridge formula weight. A load can be oversize, overweight, or both — each triggers different permit requirements and state-by-state rules.
The Legal Limits: What Triggers a Permit
Federal law establishes baseline limits for interstate highways. States may set stricter limits on state and local roads, but they must allow these federal minimums on the interstate system:
Dimensional Limits (Oversize)
| Dimension | Federal Interstate Limit | Permit Required If Over |
|---|---|---|
| Height | 13'6" (no federal law, but de facto standard) | 13'6" |
| Width | 8'6" (102 inches) | 8'6" |
| Length (semi-trailer) | 48' on interstate; 53' commonly allowed | 53' or 57'+ depending on state |
| Overall length (combo) | No federal limit on interstates | State-specific (often 65'–75') |
Weight Limits (Overweight)
| Weight Category | Federal Limit |
|---|---|
| Gross Vehicle Weight (GVW) | 80,000 lbs |
| Steer axle | 20,000 lbs |
| Tandem axle (any two consecutive) | 34,000 lbs |
| Bridge Formula (overall) | Varies by axle spacing |
Exceed any single limit and you need a permit. A 90,000-lb load within normal dimensions is overweight but not oversize. A tall piece of industrial equipment within 80,000 lbs is oversize but not overweight. A fully loaded wind turbine section is likely both.
Oversize Permit: What It Covers
An oversize permit authorizes a vehicle to travel with loads that exceed width, height, or length limits. It typically includes:
- A specific travel window (often daylight hours only; sometimes restricted to weekdays)
- An approved route — states review routing to avoid low bridges, narrow roads, and weight-restricted structures
- Escort/pilot car requirements (for very wide or long loads, or in certain states)
- Lighting and flag requirements for wide loads
- Speed restrictions
Width is often the most restrictive dimension. A load over 14' wide almost always requires escort vehicles. Some states require police escorts at extreme widths (typically 16'+ or 18'+). A load over 16' wide is often called a "superwide" — these need special coordination that goes well beyond a standard oversize permit.
Overweight Permit: What It Covers
An overweight permit authorizes a vehicle to travel above standard weight limits. Key considerations:
- Single-trip vs. annual: Most overweight permits are single-trip. Some states offer annual or multi-trip overweight permits for regularly operating heavy equipment.
- Route restriction: States will check bridge ratings along your proposed route. You may be required to detour around weight-restricted bridges.
- Axle distribution matters: A 100,000-lb load spread across many axles is more permittable than the same weight on fewer axles. Adding a jeep or booster can help distribute weight and make a permit achievable.
- Time restrictions: Spring weight restrictions (frost laws) temporarily reduce allowable weights during thaw season. These change by state and year.
When a Load Is Both Oversize AND Overweight
This is common with construction equipment, industrial machinery, transformers, and prefabricated structures. When a load exceeds both dimensional and weight limits, you need permits covering both — and the requirements compound:
- The routing must work for both the dimensional constraints and the weight limits
- Escorts may be required by the oversize restrictions
- Approved travel windows may be further restricted by the weight requirements
- Each state on the route will need its own permits covering all applicable exceedances
⚠️ Superloads: A Different Category Entirely
When a load significantly exceeds normal oversize/overweight permit limits, it becomes a superload. There's no single federal definition, but states typically classify a load as a superload when it exceeds roughly 200,000 lbs, 16' wide, or 14'+ tall. Superloads require engineering analysis, advance notice (often 10–30 days), state DOT route surveys, and often police escorts. They're a separate product from standard oversize/overweight permits — call us to discuss.
How Permits Are Obtained, State by State
Unlike trip or fuel permits, oversize/overweight permits are not standardized across states. Every state has its own:
- Portal or application process
- Routing review timeline (typically 3–4 hours for routine permits; longer for complex loads)
- Fee structure (often based on miles traveled and weight or dimension excess)
- Escort requirements
- Travel time restrictions
A multi-state route with oversize/overweight loads might require 5–10 separate state permits, each with its own application, routing approval, and fee. Coordinating these is where a permit agency earns its value.
Processing Time
Standard oversize/overweight permits typically take 3–4 hours to process, assuming no issues. Complex loads, multi-state routes, or loads approaching superload status can take longer. We recommend calling us at least 24 hours before you need to move.
What You'll Need to Get a Permit
For oversize/overweight permits, we'll need:
- Carrier name, DOT number, and MC number
- Truck configuration: number of axles, axle spacing, tire configuration
- Load description: what it is, overall dimensions (H × W × L), total weight
- Origin and full destination route (we'll help finalize this based on state requirements)
- Requested travel dates
- Escort vehicle details (if you have them)
Frequently Asked Questions
My load is 82,000 lbs but within normal dimensions. Is that overweight?
Yes. The 80,000-lb GVW federal limit applies even if every dimension is within bounds. You need an overweight permit for that load.
Do I need a separate permit for each state on a multi-state oversize move?
Yes. Unlike IRP, there's no unified multi-state oversize/overweight permit system. Each state requires its own permit, with its own routing approval, fees, and conditions.
What happens if I'm pulled over without an oversize/overweight permit?
Fines vary by state and by how much you exceed the limits, but they can run from hundreds to tens of thousands of dollars. Some states also impound loads until a permit is obtained. The permit cost is always cheaper than the fine.
Can I move an oversize load at night?
In most states, no — oversize moves are restricted to daylight hours. Some states allow nighttime moves with special lighting and additional escort requirements. We'll confirm the travel window for your specific states.
Do I still need trip and fuel permits if I have an oversize/overweight permit?
Yes. Oversize/overweight permits are separate from IRP (trip permits) and IFTA (fuel permits). If your truck needs trip and fuel permits, you still need those on top of the oversize/overweight permits.
Moving an Oversize or Overweight Load?
Don't try to navigate state-by-state oversize/overweight permits on your own. Custom Permits handles the whole route — all states, all permits — so you can focus on the move.