Pony Club Victoria



Tips onTowing



This article provides a guide to the requirements for the legal and safe towing of light trailers with light vehicles such as passenger cars, station wagons, 4WDs and utilities.
More details are provided in VicRoads Vehicle Standards Information Sheets available at VicRoads offices and on the Internet at http://www.vicroads.vic.gov.au in the Road Safety section.

What is a trailer?
Legally, a trailer can be any 'vehicle, implement, machine or other structure without its own motive power capable of being drawn by a motor vehicle'. More simply, a trailer is any vehicle you tow with your car. This includes caravans, horse floats and mobile machinery but not another motor car.

What the law requires
Trailer Construction
All trailers, like any other vehicle on the road must be roadworthy and meet specific standards even if they are not required to be registered. (Note that any trailer not used for trade purposes that is less than 3m long, weighs less than 200kg empty, is narrower than the towing car and is not specifically constructed to carry a boat is exempt from registration in Victoria). The standards a trailer must meet include requirements for brakes, lights, safety chains, mudguards etc. and can vary depending on when the trailer was built, its size and its carrying capacity. More details are provided in VicRoads Vehicle Standards Information Sheets available at VicRoads offices and on the Internet at http://www.vicroads.vic.gov.au in the Road Safety section.

Trailer Brakes
It is mandatory for all trailers that have an Aggregate Trailer Mass (ATM) more than 750kg to have brakes (irrespective of when the trailer was built). The ATM is the maximum loaded weight of the trailer. If the trailer has an ATM over 2 tonne, over-run brakes are not acceptable. These latter trailers must also have brakes that automatically apply if the trailer accidentally becomes uncoupled from the car.

Towing Ratio
The loaded trailer cannot be any heavier than the load rating of your car's towbar and it must not exceed the trailer towing recommendations of the vehicle manufacturer.
Where the vehicle manufacturer's recommendation is not available, the trailer must not exceed:

  • for trailers with brakes - 1.5 times the empty weight of the car and,

  • for trailers without brakes - the empty weight of the car. 

  • Note: Trailers with an ATM over 750kg must have brakes fitted.

Getting it together
Many trailers are used infrequently or seasonally. For example caravans and boat trailers are often not used for many months during the winter. Due to this lack of use a number of mechanical problems can develop.

For example:

  • tyres may go soft or perish

  • the wiring can corrode and the lights won't work

  • wheel bearings can dry up or rust

  • hydraulic brakes can 'gum up' and mechanical brakes seize.

While every trailer should be checked before being used, it is critical that infrequently used trailers be serviced or thoroughly checked after extended periods of inactivity.
This is also the case for the towing equipment on the car. The towbar fixing can become loose over time and loads in the boot can damage the wiring harness.
Any of these faults should be repaired immediately.

Coupling the Trailer
It is usual to couple the trailer to the car before it is loaded as it is easier to handle an empty trailer.

1. Prior to coupling, check the security of the towbar to the car, check the bolts holding the towbar tongue if it is removable, and check the ball is securely fixed to the towbar tongue.

2. Fit the trailer coupling over the tow ball and check that it seats properly and the locking mechanism has engaged by moving the trailer drawbar up and down. Check that the safety catch (or secondary locking mechanism) has locked.

3. Connect the trailer safety chain to the car. The safety chain should be short enough to prevent the draw bar hitting the ground if the coupling accidentally releases, yet still allowing adequate angular movement.
Connecting the safety chain from one side of the trailer drawbar to the opposite side of the towbar will assist in achieving this. Where the safety chain fitting on the car is well forward, crossing the safety chain over the top of the towbar tongue rather than underneath, will help.

4. Connect the lighting harness and check that all the trailer lights operate correctly.

5. If brakes are fitted check that these work also.

The balancing act
Safe Loading
Proper balance between the car and the trailer is essential for a stable, safe towing combination. This includes the distribution of the load on the trailer and the load the trailer puts onto the back of the car.
The ideal load distribution on the trailer is to have the load concentrated slightly forward of the trailer's axle fine so that between 5 per cent and 15 per cent of the trailer weight is transferred downwards on the car's towbar. Too much weight on the back of the car will tend to lift the car's front wheels resulting in poor steering and braking. Conversely, if the centre of the load is behind the trailer axle line it will tend to lift the rear of the car and result in unstable handling and fishtailing.
Note: Horse floats are generally designed for a drawbar load of approximately 15 per cent to reduce the chance of the float lifting the rear of the towing vehicle.

Where the load is spread over the trailer it is important to keep heavier items near the centre of the trailer, both lengthways and sideways to reduce sway and increase trailer stability.
The load the trailer drawbar applies to the towbar should be checked at intervals during loading. In most cases it should still be possible to lift the trailer drawbar off the towbar ball with some effort. For very heavy trailers the jockey wheel can be used to remove the load from the car and by noting the amount the rear of the car comes back up, some assessment can be made of how much load the trailer is putting on the car.
Caution: The trailer drawbar should never lift off the towbar by itself. This is a highly unsafe and unstable load configuration. 
On high trailers and caravans the load should be placed as low down as possible to reduce the tendency to sway or pitch. For example, overhead cupboards in caravans should only be used for light items.
All loads must be properly secured.

Load-Distributing Hitches
In many cases for the higher towing loads the vehicle manufacturer recommends that a load-distributing hitch be used. These hitches allow higher loads to be placed on the towbar without reducing the load on the front wheels of the car. When the load-distributing hitch is correctly adjusted, the car should sit basically the same as it did before the trailer was attached.

On the road
Towing Safely
Towing a trailer will alter the way the car performs. Acceleration will be slower and stopping will take longer, particularly when going downhill. The car may not go around bends as well and the trailer will cut in more on tight corners. Side winds and passing traffic (particularly large trucks) may affect stability as can bumps and undulations in the road. Consequently, towing a trailer can be more stressful and fatiguing for the driver.

Safety Tips

  • Maintain a greater space to the vehicle in front to allow for the longer stopping distance

  • Provide extra distance when overtaking other vehicles as this will take much longer.

  • Select a lower gear on long or steep downhill grades to increase control and conserve the brakes.

  • Avoid sudden lane changes or swerving to reduce the risk of developing sway. Gentle manoeuvring (and braking) is most important with horse floats as sudden movements could injure the horse. Sudden movements may also make the horse move which could cause the float to sway.

  • Be cautious in high winds or when passing large oncoming vehicles as buffeting may induce sway.

  • If sway develops, the car brakes should not be applied (except as an absolute last resort). A steady speed or slight acceleration should be maintained until the sway has ceased. Alternatively, if the trailer brakes can be applied independently, gentle application of the trailer brakes will restore stability.

  • Keep an eye on following traffic as they will have more difficulty passing you and a long queue can quickly develop. Where possible make provision for this queue to overtake you. On some narrow roads this may mean pulling over and stopping occasionally.

  • Take more frequent rest breaks or driver changes. At these rest breaks and/or driver changes the condition of the car and trailer should be checked.

More details are provided in VicRoads Vehicle Standards Information Sheets available at VicRoads offices and on the Internet at http://www.vicroads.vic.gov.au in the Road Safety section.