Caravan safety: What to check before your next road trip

Whether you’re a seasoned caravanner, or a newbie, it’s important to conduct necessary checks of your caravan and towing vehicle before you hit the road to make sure they meet safety requirements.

Towing capacity

Your vehicle has a maximum towing capacity, which must not be exceeded or it becomes unsafe and illegal to tow. You can find out your vehicle’s maximum towing capacity in your owner’s manual. If you need to tow more than the maximum towing capacity, you may need to seek advice from a licensed certifier.

Towing vehicles must be equipped with:

  • Towbars and couplings suitable to type and capacity
  • Electrical sockets for lighting
  • Brake connections
  • Safety chains if driving in snow or icy conditions
  • If you have a large caravan, you may also be required to have extra mirrors as well.
  • While not essential, it is recommended to install a ‘trailer sway control’, which is an electronic safety feature that helps reduce dangerous swaying of the caravan.

Your caravan’s total loaded mass also must not exceed any of the following:

  • Rated capacity of the towbar and tow coupling
  • Maximum towing capacity of the vehicle (GCM)
  • Maximum fully loaded carrying capacity of the caravan (ATM)
  • Maximum rated carrying capacity of the tyres.

These capacities will be specified by your towing vehicle manufacturer, towbar manufacturer (if made by a different manufacturer to the vehicle), and the caravan manufacturer.

These capacities can vary significantly, so if you change your towing vehicle, towbar, or caravan (or never checked these before), then take the time to do so before your next trip. Not complying with these requirements could cause an accident, injury, or worse.

Weighing your caravan

Overweight caravans are extremely unsafe on the road. It’s vitally important to understand your max weights for your caravan, tow bar, and towing vehicle to make sure that you aren’t breaking the law, putting too much strain on your chassis and running gear, breaching your insurance, and risking a hefty fine.

Your towing vehicle, tow ball and caravan will each have their own weights that must be measured before you depart on your journey. You can weigh these components either using a public weighbridge or using a mobile weighing service that comes to you.

What you should weigh before you depart:

  • Tare mass: This is the total mass of your caravan or vehicle unoccupied, without any load (such as awnings, mattresses, TVs or additional gas bottles) and with all required fluid reservoirs filled to nominal capacity. You can find the tare mass weight for your caravan or towing vehicle on the vehicle plate or in the manufacturer’s handbook.
  • Tow ball mass (or tow ball load): This is the maximum load that can be put on the tow ball of the vehicle. You can find the maximum tow ball capacity in your coupling manufacturer’s handbook. Use a ball weight scale to measure the tow ball mass with your caravan loaded. It must not exceed the tow ball mass capacity.
  • Aggregate Trailer Mass (ATM): This is the maximum weight of the loaded caravan. You can find the maximum ATM of your caravan. To measure your ATM, unhitch your caravan from the towing vehicle and rest it on its jockey wheel while fully loaded. This must include everything you will be travelling with including full water and fuel tanks, furniture and electronics, and luggage.
  • Gross Trailer Mass (GTM): Measuring GTM is similar to ATM, except the fully loaded caravan is hitched to the car when you weigh it. You can find the maximum GTM on the vehicle plate or in the manufacturers handbook. The GTM of the caravan is transmitted to the ground only by the caravan tyres and does not include the mass distributed to the towing vehicle through the coupling.
  • Gross Vehicle Mass (GVM): This is the total mass of a fully loaded towing vehicle as specified by the manufacturer and is also referred to as Maximum Loaded Vehicle Mass (MLVM). To measure GVM, weigh your fully packed towing vehicle (don’t forget passengers) with the caravan hitched. You can usually find GVM on the vehicle’s weight placard or in the owner’s manual.
  • Gross Combination Mass (GCM): This is the total combined mass of your fully loaded caravan and towing vehicle. Not all vehicles provide a maximum GCM, but you can check for it in the vehicle manufacturer’s guide. To measure GCM, weigh your fully loaded caravan hitched to your full loaded towing vehicle together.

Loading caravan

It’s important you do not exceed any of the above weight limits when loading your caravan.

Use the following formula to calculate your caravan payloads:

  • ATM ­- caravan tare mass – tow ball mass = maximum caravan payload

Weight can add up quickly, so it’s important to weigh each individual item you intend to pack (including optional extras to the caravan such as awning, air-conditioning unit, spare tyre, gas bottle, and water) and make sure the total is under your maximum caravan payload.

Ensure the heaviest items are packed low and over the caravan’s wheel axles and lightest items are up high and distributed across the caravan. This will help prevent any snaking or swaying while driving.

Roadworthy & registration

All vehicles and caravans will need to comply with your state or territory’s registration and roadworthy requirement. This will include rear number plates and lights must be visible on the trailer and on the towing vehicle when not connected (not blocked by the towbar).

If the combined length of the caravan and towing vehicle is 7.5m or greater, a ‘DO NOT OVERTAKE TURNING VEHICLE’ sign must be attached to the rear of the caravan.

Safety checklist

Before you head on a road trip, use this safety checklist to check you’re ready to go. Do this ahead of time in case any repairs are needed.

Brakes and Tyres:

  • Does the caravan tyre pressure meeting manufacturer’s specifications?
  • Do you have a spare wheel packed and is it operational?
  • Have the wheel nuts been tightened to manufacturer’s specifications?
  • Are wheel chocks and jack stands working? This is in case a tyre change is needed.
  • Are caravan wheel bearings correctly adjusted and lubricated?
  • Do the caravan tyres have the legal thread depth?
  • Are the tyre casings cracked or perished?
  • Are the brakes operating correctly on all axles of the caravan?
  • If electric brakes are fitted, are they charged and is the charging system working?


  • Are the caravan lights, number plate and registration clearly visible?
  • Are the caravan light connections secure and all the lights working?


  • Are all the towing components in good condition (i.e. no cracks or large dents) ?
  • Are the safety chains correctly connected?
  • Are the front and rear corner stablisers in the up position?
  • Do the coupling socket and ball match each other?
  • Is the coupling correctly and securely fastened?
  • Are towing mirrors correctly fitted and adjusted? You should be able to see clearly down both sides of the caravan as well as behind it.


  • Have you checked the loaded mass does not exceed the below:
    • Rated capacity of the towbar and tow coupling
    • Maximum towing capacity of the vehicle (GCM)
    • Maximum fully loaded carrying capacity of the caravan (ATM)
    • Maximum fully rated carrying capacity of the tyres

Last checks

  • Are gas taps and cylinders switched off?
  • Is the fridge door closed and locked, set to 12V mode and travel catch engaged?
  • Are all lights off at their switch and all appliances unplugged and secured in travel position?
  • Are taps and shower control switched off?
  • Has the mains power been isolated?
  • Has the water system been drained? If so, disconnect it now.
  • Are all waste tanks empty and water pumps turned off?
  • Are the awnings stowed away and locked in travel position?
  • Have the entrance step and stabiliser legs been retracted and in the travel position?
  • Are roof hatches, windows, doors, cupboards and stone shields secure?
  • Are all power cords, water hoses and other cords disconnected and securely packed away?
  • Is the TV antenna in travel position?
  • Are all loose items secured so they don’t move during the journey (this could upset balance of caravan or injure vehicle occupants)?
  • Has the jockey wheel been removed from clamp and stored in the boot of the car or caravan? Or if it’s in a swivel mount, is it locked in the travel position?
  • Has the caravan handbrake been released correctly?
  • Do you know the clearance height of your caravan?

/Public Release. This material from the originating organization/author(s) may be of a point-in-time nature, edited for clarity, style and length. The views and opinions expressed are those of the author(s).View in full here.