Oversize/Overweight Permit
An oversize or overweight (OS/OW) permit is a state-issued authorization that allows a vehicle to operate above standard size or weight limits. Permits are required when loads exceed 8.5 feet wide, 13.5 feet tall, 53 feet long, or 80,000 lbs gross.
In Depth
OS/OW permits are required for every state the load passes through — a coast-to-coast superload may require permits from 10+ states. Permit requirements, routes, travel hours, and pilot car requirements vary by state. Some states restrict oversize movements to daylight hours and prohibit weekend or holiday travel.
Permit categories include single-trip (one move), annual blanket (repeated trips within a state at specific dimensions), and superload (extreme dimensions requiring special route surveys). Costs range from $15–$200+ per state depending on dimensions and weight.
Permit services (like Nationwide Permits or Oversize.io) specialize in coordinating multi-state permits, route surveys, and pilot car arrangements, charging $150–$500 per permit set for complex loads.
Usage Example
Example: 'My windmill blade load was 180 feet long — I needed permits in 4 states, 2 pilot cars, and a police escort through major cities.'
Related Calculators
Related Terms
Gross Vehicle Weight Rating (GVWR)
GVWR (Gross Vehicle Weight Rating) is the maximum safe operating weight of a single vehicle as specified by the manufacturer, including the vehicle itself and its maximum cargo load. For combination vehicles (truck + trailer), the combined GVWR is called the Gross Combination Weight Rating (GCWR).
Axle Weight
Axle weight is the total load transmitted to the road through a single axle or tandem axle group. Federal law limits single axles to 20,000 lbs and tandem axles to 34,000 lbs, and states may impose stricter limits.
Bridge Formula
The Federal Bridge Formula (also called Bridge Formula B) is a federal regulation that limits the weight a commercial vehicle can carry based on the number of axles and the distance between them, to prevent damage to bridges and road infrastructure.
Pilot Car
A pilot car (also called an escort vehicle) is a vehicle that travels ahead of or behind an oversize load to warn other motorists, verify clearances, and comply with state permit requirements. Most states require pilot cars for loads exceeding 14 feet wide or specific length thresholds.
Frequently Asked Questions
When do I need an oversize permit?
When your load exceeds 8.5 ft wide, 13.5 ft tall, 53 ft long, or 80,000 lbs gross. Requirements vary by state.
How much does an oversize permit cost?
$15–$200+ per state depending on dimensions. Complex superloads requiring route surveys and engineering analysis cost significantly more.