RAC Guide to Towing

How to tow safely

Whether you are towing a horse box, a caravan or a boat it is imperative that you take special care to ensure the safety of yourself and others.

Towing rules

• When towing a trailer you are restricted to a maximum speed of 50mph on single carriageway roads, and 60mph on dual carriageways and motorways, provided no lower limit is in force. You are not allowed to use the outside lane of a three or more, lane motorway when towing, except where there are lane closures which restrict the lanes to two or less, or when instructed to do so by the Police.
• If you tow a small trailer without brakes, the weight of the trailer is limited to 50% of the kerb weight of the car or 750kg, whichever is less.
• When towing larger trailers that have brakes fitted, the weight of the vehicle should not (as a rule of thumb) exceed 85% of the kerb weight of the towing vehicle.
• Most vehicle manufacturers state the maximum towing limit in their hand books, but you must bear in mind the total weight including passengers and luggage, also any items put in the caravan or trailer. The weight can soon add up.

Before towing

• Make sure your trailer is regularly serviced and maintained. It is not wise to leave your caravan, horse box or trailer unused for the majority of the year before taking it out on the road without checking it for serviceability, brakes and tyres in particular.
• If your trailer has brakes, a common problem that may occur is that brake cables and linkages could seize. This may cause the brakes to bind, over heating the wheel bearings. This may result in the wheel, complete with the hub assembly, parting company with the trailer.
• Check the condition of tyres and tyre pressures regularly.
• If you are towing a large high sided trailer or caravan you may require extended door mirrors. These will help visibility along both sides of your vehicle and trailer.
• You will need to be aware that the vehicle and trailer will take longer to stop, accelerate and turn than a vehicle on its own.

Loading your trailer

• Many problems associated with towing a trailer are caused by incorrect loading.
• Try to put all heavy items over the axle and make sure they are secured to prevent movement when cornering or braking.
• If possible, put heavier items in the car and larger lighter items in the trailer.
• Consult your trailer and car handbooks to establish the correct "nose weight" for your trailer. Most cars state 50kgs to 75kgs.
• To check your nose weight place a flat piece of wood on your bathroom scales (to spread the load and prevent damage to the scales).
• Lower the jockey wheel of the trailer onto the centre of the wood and adjust the angle of the trailer so that it is level.
• To be more accurate, put a length of wood between the coupling head and the flat piece of wood on your scales ensuring the trailer is level.
• Check the weight shown on the scales and compare with your car / trailer requirements.
• If incorrect adjust the trailer load to compensate.
• Finally, check the load is secure and can't move. It is always good policy to recheck your load after a few miles to confirm everything is secured properly.

Hitching up

• If the trailer is heavy to handle it is far easier to reverse the car up to the trailer.
• If you are in a tight position and wish to manually manoeuvre a double axle trailer, it will be easier, if you raise the front axle off the ground by using the jockey wheel.
• This would result in the trailer only having three wheels on the ground making it far easier to turn.
• Adjust the jockey wheel so that the coupling head is approximately 2" to 3" above the ball hitch on the back of the car.
• It is helpful to have a companion to guide you when reversing your vehicle, so that the ball is underneath the coupling head of the trailer.
• Lower the jockey wheel and lock the coupling head onto the ball, making sure it is properly locked on. Continue winding the jockey wheel to fully retract it into its outer case. Release the clamp lever and raise the whole unit and firmly reclamp, attach break away cable/securing chain to the hook on the tow bar, not ball, and connect electrical plugs to car.
• Finally, check all lights are working, cables do not drag on the road and the trailer hand brake is off.
• Stand back from the vehicle and trailer and check that both are level.
• If the back of the car is too low and the nose weight is correct and the car tow ball is the correct height, then you have either have got too much weight in the back of the car or the car springs need strengthening with spring assistors.

Manoeuvring

• Remember to allow for the extra length and width of your vehicle and trailer when taking corners or manoeuvring in a confined space.
• Take a wide line to ensure the trailer does not clip the kerb, keeping a watchful eye on both door mirrors. Reversing a small trailer is far more awkward than a large one as it is a lot more sensitive to steering, and can be difficult to see.
• When reversing into a space, turn the steering wheel the opposite way to normal to start the trailer turning, then slacken off and turn the normal way to enable the car to follow the trailer.
• If you oversteer your trailer it could jack-knife and cause damage. Therefore, stop, pull forward in a straight line, and retry.
• Don't give up, keep practising.
• It would be useful to practise in a large open space before you are competent enough to go out on the road.

Snaking and stabilisers

• As long as the trailer is evenly loaded, nose weight is correct and the whole outfit sits level on the road you are unlikely to experience a problem with snaking, except for high sided trailers/caravans where side winds or passing HGVs can unrest the trailer.
• You may need a stabiliser. These reduce snaking by increasing the turning friction between towing vehicle and trailer. However a stabiliser will not compensate for bad loading, weight distribution.

And finally...

Further advice on towing and other motoring related concerns is always available to RAC Members. Click here for the RAC

All this information on this page is accredited to the RAC National Technical Centre