April 2008





Towing – keeping it legal

Trailers and cars being towed behind motorhomes are a common sight. But adding an extra load to what is probably the largest vehicle most of us are likely to drive, means that not only must additional care be taken on the road – there are also a range of rules and regulations that have to be understood and followed.

What am I licensed to tow?

It should go without saying that you can only tow a trailer or car if you hold a full driving licence. Do not be tempted to tow anything if you are driving on L plates – you will be pulled over and prosecuted.

Anyone holding a driving licence issued before 1 January 1997 can drive a vehicle with a maximum authorised mass (MAM) of up to 7500kg and tow a trailer. However, the combined (train) weight of your motorhome and trailer must not exceed 8250 kg. Nor can the weight of the trailer when it is fully loaded exceed the unladen weight of your motorhome.

If you passed your test after 1 January 1997, you can only drive vehicles with a MAM of up to 3500kg, with eight seats or less, and tow a trailer weighing up to 750kg. If you really want to exceed these limits, you can take an additional test to demonstrate that you are capable of handling a larger trailer. For more information go to www.dvla.gov.uk

Safety first

Don’t forget though, these limits apply to you – not to your motorhome. You may be licensed to drive a vehicle and tow a trailer with a train weight of 8250kg but don’t forget to check the maximum train weight of your motorhome. If you look on the Vehicle Identification Number (VIN) plate, you will find the gross train weight (GTW) and the maximum gross weight (MGW) printed there. Just deduct the MGW from the GTW and that should give you your vehicle’s maximum towing limit.
Before fitting a towbar, you also need to measure the wheelbase of your motorhome (from the centre of the front axle to the centre of the rear axle) and the overhang (from the centre of the rear axle to the very back of the vehicle). The overhang can be up to 60% of the wheelbase but any towbar needs to fit within that limit.


The Society of Motor Manufacturers and Traders Limited (SMMT) points out in its guide Towing and the law, “A properly fitted, good quality towbar with the correct specification for the vehicle is essential. Anything less can compromise safety”. Do not be tempted to cut corners: you could be endangering yourself, your family and others.

Towbars, towballs and other couplings fitted to cars registered on or after 1 August 1998 must be approved under EU Directive 94/20/EC – Mechanical Coupling Devices. Motorhomes appear to be currently exempt form this law. Talk to ten people and you get ten different answers as to when the UK will fall in line with Europe and make this a law.

However, if your towbar, its mounting points or electrical connections are found to be in a poor condition by the police, you could be prosecuted under the Road Traffic Act 1988 for driving a vehicle/trailer in an ‘unroadworthy condition’. So if your towbar was fitted 10 or more years ago, do check it regularly.

If your towbar is EC-approved, it must also be marked with the ‘S’ value - the maximum vertical static load in kg - and the ‘D’ value - a figure calculated from the maximum gross weight of the trailer and the maximum gross weight of the towing vehicle and expressed in kN. The maximum ‘S’ value and gross vehicle and trailer weights recommended by the manufacturer of your motorhome must not be exceeded. You can look up this information in your vehicle handbook. The SMMT points out that figures marked on your towbar for gross vehicle or trailer weight are likely to be the absolute maximum for that range. So do check with your dealer whether or not individual models within the range have lower limits.

The other legal requirement that anyone buying a towbar needs to be aware of, is that there must be a way of attaching a breakaway cable for braked trailers or secondary coupling cable if you are towing an un-braked trailer manufactured after 1 January 1997. If there is no attachment point on your towbar, the SMMT advises that you contact the towbar manufacturer for advice.


• Trailers only need brakes if their MAM is more than 750kg.

• Unbraked trailers can only be towed by vehicles with a MGW of at least twice the in-use weight of the trailer. So what that means in practice is that if your motorhome has an MGW of 1000kg, you can only tow an unbraked trailer of 500g, regardless of the trailer’s own MAM.

• There is no registration system in the UK for trailers and there is no additional road tax to be paid by the towing vehicle.

• There is no legal requirement for a braked trailer up to 3500kg to be fitted with a manufacturer’s plate for use on UK roads but most trailers do carry one. Unbraked trailers however, must be clearly marked with their unladen weight, MGW and year of manufacture.

• Trailers must a carry number plate, comprising black letter on a reflective yellow background, that tallies with the rear plate on the towing vehicle. This must be illuminated at night.

• If you have an unbraked trailer manufactured after 1 January 1997, you must fit a secondary coupling between the trailer and your vehicle. This is a chain or cable that maintains the connection between the two, should the primary coupling fail.

• The law also requires that if you have a braked trailer manufactured after 1 October 1982, it must be fitted with a breakaway cable. This means you can still apply the brakes if the trailer is separated from the towing vehicle.
• If your trailer is being towed by a 3.5 tonne motorhome then the trailer dimensions must be less than 7m long x 2.3m wide. Anything larger must be towed by a heavier vehicle.

Towing a second vehicle

It is generally accepted that the best and safest way to tow a car behind a motorhome is on a trailer designed for this purpose.

The alternative is to use an A-frame but as with many aspect of the towing topic, the jury is still out on whether or not these are a safe (and legal) way to tow a second vehicle. When a car is being towed by a motorhome and its wheels are in contact with the road the Department of Transport treats the A-frame and car as one vehicle and the law applies in the same way as it would to a trailer. This means that the car and A-frame must meet the same technical requirements as trailers when used on UK roads and this applies in particular to lights and brakes. If these requirements are met, the Department of Transport regards the use of A- frames as acceptable on UK roads under current legislation. However, there has yet to be a test case in the courts.

Like a trailer, unless a car has a MAM of less than 750kg (the FunTec and Aixam fall into this category) it must be towed using a braked device and the car’s lights must work in tandem with those on the towing vehicle. UK legislation also requires the fitting and use of a secondary coupling system in which a trailer is stopped automatically if the main coupling separates while the combination is in motion. In the case of trailers up to a maximum mass of 1500kg, the drawbar must be prevented from touching the ground and the trailer able to retain some residual steering.

If you are thinking of using an A-frame, the DfT recommends asking your supplier for a written declaration stating that your installation meets all UK legislative requirements. You should also talk to your insurers to let them know that this is how you are towing your car.

Remember, this is simply the Southdowns Team trying to offer helpful advice based on our knowledge and our experience. This is not necessarily a statement of fact. We do not currently employ any lawyers in our showroom or in our workshop and the only place law is confirmed is in the court!!