How to Measure Your Vehicle for Oversized Transport

Accurately measuring your vehicle is the foundation of a safe, legal, and cost-efficient oversized transport. Whether you’re shipping a motorhome, bus, or heavy truck, even a few inches can mean the difference between a standard permit and a costly “super load” classification.

“Even a few inches of extra height can change your permit class or require pilot cars,”
— Mark Dugger, Operations Manager, AutoStar Transport Express.

Knowing your exact dimensions ensures you get precise quotes, avoid permit rejections, and help carriers plan the right trailer and route for your shipment.

Why Accurate Measurements Matter

Shipping oversized vehicles involves strict federal and state limits on size and weight. The FMCSA and state DOTs require accurate height, width, and length information before issuing a permit.
Errors can lead to:

• Permit rejections or route delays
  
  

• Unexpected fees for detours
  
  

• Carrier refusals at pickup
  
  

• Safety risks from bridge or clearance issues
  
  

If you’re unsure whether your RV, bus, or truck qualifies as an oversized vehicle, you can verify dimensions and permit requirements directly with the large vehicle specialists like AutoStar Transport Express. Their team helps owners calculate legal limits before transport.

What Dimensions You Must Measure

Before requesting quotes or applying for permits, you’ll need these six key measurements:

1. Overall Length

Measure from the frontmost point (often the bumper or fender tip) to the rearmost point (tailgate, ladder, or trailer hitch).
Include:

• Front and rear attachments (racks, winches, bumpers)

• Trailer tongues or tow frames
  

👉 Tip: Always measure with accessories installed if they’ll remain during transport.

2. Overall Width

Measure the widest point across the vehicle — typically mirror to mirror or fender to fender.

• Include side mirrors, steps, or toolboxes if they can’t be folded.

• Some states exclude mirrors or safety lights from “legal width,” but still note them for transport planning.

3. Overall Height

Measure from ground level to the highest point — often the top of an A/C unit, antenna, or roof vent.
Use a plumb line or level board placed on the highest spot, then measure vertically to the ground.

Pro tip: Measure on a flat, level surface. Even a slight slope can add 2–3 inches of error.

4. Front and Rear Overhang

If your vehicle or load extends past its base frame, measure the distance from the wheel center to the outermost edge in both directions. Overhang affects trailer loading balance and road legality.

5. Ground Clearance

Measure the lowest point under the vehicle (exhaust, oil pan, hitch). Low clearance impacts loading ramps and trailer type — especially for long wheelbase RVs or buses.

6. Weight (Total and Per Axle)

Use a certified scale or weighbridge. Note both gross vehicle weight and axle-by-axle distribution, since permits and routing often depend on axle load.

Tools & Methods for Accurate Measurement

Always measure in feet and inches, but record metric equivalents for permit applications.

Step-by-Step Measuring Procedure

Follow this field-tested order to ensure consistency:

1. Park on flat, level ground – ideally a concrete driveway or lot.
   
   

2. Length: measure front to rear; include fixed attachments.
   
   

3. Width: measure at several points — base, mid-height, and top — to confirm widest section.
   
   

4. Height: use a board and plumb bob from roof to ground, or a laser level for tall units.
   
   

5. Overhangs: record both front and rear separately.
   
   

6. Ground clearance: measure at lowest midpoint.
   
   

7. Take photos – capture each measurement with a visible measuring tape or laser reading.
   
   

Save these photos and values in a simple chart or email for easy quote sharing.

How Much Buffer Should You Add?

Vehicles shift slightly under load or due to tire/suspension compression. To stay safe:

• Add 2–4 inches to your measured height
  
  

• Add 1–2 inches to width
  
  

• Add 6–12 inches to overhang for long loads
  
  

This small buffer prevents permit denials or trailer fit issues.