Learn about towbar standards and requirements for towing trailers and caravans, along with guidance on A-frame towing and towing agricultural implements.
Building a trailer
Under the Commonwealth’s Road Vehicle Standards (RVS) legislation, manufacturers and importers of trailers with an aggregate trailer mass (ATM) of 4.5 tonnes or less (low ATM trailers) will need an approval before they can provide a trailer type to the Australian market.
For example, caravans, box trailers and boat trailers.
Under the previous Motor Vehicle Standards Act 1989, trailer manufacturers and importers could self-certify that a trailer complies with Vehicle Standards Bulletin 1 (Version 5) (VSB1—Building Small Trailers). This certification was included on the trailer's identification plate, but it wasn't necessary to notify the government. This has changed.
Now, every road vehicle including trailers, will need to have vehicle and compliance information listed on the Register of Approved Vehicles (RAV) online database. Only then can they be provided to Australian consumers for the first time.
The vehicle standards for trailers will still be subject to the applicable Australian Design Rules (ADRs). The Vehicle Standards Bulletin 1 has been updated to Revision 6 and has easy-to-read information about the ADR requirements for most trailers and the most used ways to show they comply.
Some manufacturers may need to refer directly to the ADRs to confirm they comply.
Two pathways are available:
- concessional RAV entry approval, and
- vehicle type approval.
These pathways have different eligibility criteria and approval conditions, if an approval is granted.
Further information about low ATM trailers is available via the Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts.
In addition, CI-119C: Safety chains for new trailers under 4,500 kg ATM (Circular to Industry) - PDF, outlines the standards and requirements for trailer safety chains. A suitable safety chain must be used with trailers - even trailers under 2,500 kg must be fitted with at least 1 chain.
Modification to a light trailer or caravan (Aggregate Trailer Mass 4500kg or less)
When a light trailer including a caravan has been or in the process to be modified away from the original manufacturer’s specifications, or its form when first licensed it will require the approval by the Department of Transport and Major Infrastructure (DTMI) Vehicle Safety and Standards section (VSS).
A light trailer including a caravan may be modified using new or second-hand parts provided it remains compliant with the relevant vehicle standards including, the Australian Design Rules (ADR), Western Australian (WA) state regulations and Vehicle Standards Bulletin 1 (VSB1).
If you’re unsure whether the modifications you are planning for a light trailer or caravan will affect its compliance with the vehicle standards, advice should be sought from one of DTMI’s approved automotive consultants listed in IB-102s: Automotive Consultants (Information Bulletin) - PDF, or the original trailer manufacturer.
The chassis/frame or any damaged component from a statutory write-off vehicle including its identifier mustn't be used to modify or construct a trailer or caravan. Application to modify a light trailer or caravan must be made to VSS by either the following stipulated methods:
- an original letter from the trailer/caravan original manufacturer specifying the modifications and confirming the modified trailer/caravan maintains compliance with the applicable vehicle standards. This letter shall be emailed to tps@transport.wa.gov.au, or
- online via the Vehicle modifications form on Modify a light vehicle: Complex (engineering).
Once approval has been granted, the trailer/caravan will require a full vehicle inspection.
Motorcycle trailers
Before you attach a trailer to your motorcycle, you’ll need to understand the rules that apply to your vehicle. It's also important that you know how to equip your motorcycle, as well as how to fit and load what you intend to tow. For detailed guidance, refer to IB-12B: Motorcycle trailers - Construction and use (Information Bulletin) – PDF
Towing agricultural implements
If you’re planning on towing agricultural implements, there are specific rules and regulations in place governing how to do so.
The following fact sheets provide a broad range of information about towing agricultural equipment and escorting vehicles that are towing agricultural implement, including:
- what constitutes agricultural equipment
- permits and vehicle licence requirements
- lighting requirements
- warning signs and signals
- the operation of pilot vehicles.
Towing trailers and caravans
Before towing a trailer or caravan, you need to understand your vehicle's towing capabilities, otherwise you risk costly damage and accidents.
Tare weight
The tare weight of a vehicle is the weight of a vehicle when it is unladen. The tare weight includes all necessary oils, water, coolants, 10 litres of fuel and any equipment required to operate the vehicle.
Gross Combination Mass (GCM)
GCM is the maximum allowed loaded weight of the towing vehicle plus the maximum allowed loaded weight of the trailer/s or caravan.
The maximum allowed loaded weights are specified by the vehicle manufacturer and include all luggage, passengers, fuel, equipment, etc. that may be in the vehicle.
It’s also important to ensure the vehicle manufacturers tow capacities, or tow bar/ball manufacturers capacities (whichever is the lesser) are not exceeded.
Learn more about Gross Combination Mass (GCM) and Gross Vehicle Mass (GVM) via our GVM and GCM FAQs page.
Tow ball down weight
Tow ball down weight is the weight applied down onto the tow bar. The maximum tow ball down weight should not be exceeded.
How to equip your vehicle
It's also important that you understand how to equip your vehicle, as well as how to fit and load what you intend to tow.
Read our Safe towing guide - PDF to find out more on the subject, including:
- how much you can safely tow.
- laws that you need to be aware of.
- overtaking rules.
- towbar and trailer safety requirements.
- safe driving and loading tips.
Towing using an A-frame
An A-frame can be used to tow another vehicle which has its front wheels on the road and is connected to the towbar of the towing vehicle by a triangular shaped frame.
You'll need to complete and submit the A-frame Towing Application Form E182 - PDF to apply to tow a motor vehicle using an A-frame.
An A-frame attachment is considered a modification. Our A-frame Towing (Brochure) - PDF provides information on:
- regulations and requirements
- Australian road rules
- coupling and chain design
- towing capacity
- braking requirements
- lighting and steering requirements.