Understanding Caravan Size Limits and Transport Permits

4 min read

Note: This is a general approach and each carrier and service company handle things differently. 

When it comes to towing a caravan interstate or across Western Australia, it’s important to know the rules. Most caravans fit within standard limits and don’t need a special permit. But once your rig exceeds certain dimensions, you’ll need an Oversize/Overmass (OSOM) permit from NHVR or Main Roads WA.

Standard Caravan Dimensions 

Across Australia, general rules apply for caravans and trailers:

• Length: Must not exceed 12.5 m
• Width: Must not exceed 2.5 m
• Height: Generally restricted to 4.3 m, except on some WA highways where 4.6 m may be allowed

If your caravan stays within these dimensions, you can travel without a special permit.

When a Special Permit Is Needed

Exceeding Standard Dimensions

If your caravan is taller than 4.3 m (or 4.6 m on approved WA routes), wider than 2.5 m, or longer than 12.5 m, it becomes an oversize load. In such cases, you must obtain an OSOM permit before taking to public roads.

State-Specific Scenarios

• WA (Western Australia):
  Travel on non-approved routes with loads over 4.3 m tall, 2.5 m wide or 12.5 m long requires permits, applied directly to Main Roads.
  
• Victoria and NSW:
  Tolls or restricted zones may also require a permit if your caravan exceeds local thresholds (e.g. >4.9 m high for railway crossings in Victoria)
  

Key Dimensions and Limits

What the OSOM Permit Covers

An OSOM (Oversize Overmass) permit ensures that you’re legally authorised to transport an oversized caravan in Australia and outlines several important conditions. It typically includes an approved travel route that avoids hazards such as low bridges, narrow roads, or tight corners. The permit may also specify time-of-day travel restrictions, often requiring transport to occur outside of peak hours to minimise traffic disruption.

Depending on the size and weight of the caravan, the permit might mandate the use of escort vehicles for added road safety. Additionally, the permit ensures compliance with relevant safety gear, proper escort signage, and applicable speed limits, helping you stay in line with national and state transport regulations.

Tips for Safe and Legal Caravan Transport

When preparing your caravan for transport, it’s essential to measure it accurately,including all attached accessories such as air conditioners, bike racks, and awnings to ensure compliance with dimension regulations. Careful route planning is also vital to avoid low-clearance structures and to adhere to any state-specific transport restrictions along the way.

For peace of mind, it’s worth consulting with professionals. At National Car Movers, we assist in comparing transport options and offer tailored advice for moving non-standard caravans across Australia. Whether you’re considering towing the caravan yourself or using a professional carrier, our interstate caravan transport services can help you get the job done legally and efficiently.

If your caravan forms part of a larger setup or is paired with a trailer, consider our interstate trailer transport services for bundled, compliant solutions.

Stay Compliant When Moving Your Caravan

Most caravans won’t need a permit but if you’re towing a rig that exceeds 12.5 m long, 2.5 m wide, or taller than permitted (4.3 m—or 4.6 m in WA), you must get an OSOM permit before travelling. Stay on the right side of the law, stay safe, and if you need help figuring it out,

National Car Movers can guide you through the permit process and offer compliant transport solutions. In addition to caravan relocation, we also provide reliable car transport services across Australia, ensuring your vehicle or recreational setup gets where it needs to go,legally and hassle-free. Explore our caravan and car transport services online or call us on 1300 396 099  we’re here to help.