The legal use of trailers is an area that continues to be clouded with misinformation. However, a recent booklet produced by the Road Safety Authority (RSA) provides useful clarification.

There are three issues around the area of trailer use with a car or a 4x4: driving licence, the towing capacity of the car/4x4 and the maximum authorised mass (MAM) of the trailer itself – how much weight it is designed to carry.

Since 1989, drivers towing trailers that weigh over 750kg are required to sit a separate test in addition to their standard B driving licence test. The RSA says that, as a general rule, a category B licence would not entitle the holder to tow a horsebox or a livestock trailer because the design gross combination weight (DGCW) of the car and trailer would exceed 3,500kg.

The BE driving licence allows drivers to tow a fully loaded trailer weighing up to 3,500kg, provided the weight of the trailer being towed does not exceed the manufacturer’s specified towing capacity for your towing vehicle. Some of the larger 4x4s are the only vehicles that are suitably rated for this maximum towing figure. The RSA has confirmed that these light-type trailers – that is, those with a MAM not exceeding 3,500kg – are not required to undergo a compulsory roadworthiness test.

The towing rating on your car or 4x4 dictates the maximum weight that your vehicle is allowed to tow. This is shown on the vehicle weights identification plate, which is usually found as a small sticker on the inside of the door panel when you open the driver’s door. This is fitted to every car and van sold in Europe.

The maximum towing weight is also clearly stated in the specifications section in the owner’s manual. You are obliged to make yourself aware of it.

The maximum weight of the trailer is shown on the manufacturer’s plate, usually fixed to a section of the trailer draw-bar. You should not exceed the weight for which the trailer is designed and manufactured.

Typically, an Ifor Williams TA5 (12ft x 6ft) livestock trailer, which is the one that we had during our recent 4x4 tests, will have a maximum gross weight rating of 3,500kg – that is the total weight for the trailer and its load. The trailer’s empty weight can be either 1,005kg or 1,135kg depending on the type of ramp used. This gives a load capacity of not more than 2,495kg or four 600kg animals.

There is no need to have a 4x4 to tow a double/twin-axle livestock trailer, providing your car is rated to suit the load. Some larger cars are rated at a 2,100kg towing capacity and, as a result, they can be used to tow bigger trailers, but not when fully loaded in many cases.

trailer weight identification plates

Figure 1 above shows a car/4x4 vehicle weight identification plate. It is usually found as a small sticker on the inside of the door frame panel when you open the driver’s door.

In this case, I’ve used the 2015 Volkswagen Touareg, which has a maximum towing rating of 3,500kg with a braked trailer, as seen in the driver’s manual/handbook.

The towing rating is typically the gross combination weight minus the gross vehicle weight (here 6,390kg - 2,880kg = 3,510kg), which is easy for any vehicle owner to work out.

Figure 2 shows a sample of a trailer towing rating plate from a Nugent twin-axle cattle trailer.

So, while the Volkswagen Touareg may be rated to tow 3,500kg, the Nugent trailer is only rated to carry 2,700kg, which is the weight of the trailer and its load. The combination of the two is 2,880kg + 2,700kg = 5,580kg

In summary, the trailer’s gross vehicle weight (GVW), ie the weight of the trailer plus the load being carried, should not exceed the towing capacity of your towing vehicle, as shown on the sticker inside the front driver or passenger door and shown in the specification section of the manual, and it should not exceed the trailer’s rated maximum weight

New RSA Trailer Booklet

The RSA released a new booklet entitled Road Safety Advice and Driver Licensing Rules for Drawing Light Trailers at the Ploughing. This contains practical advice and is an essential reference for those involved in towing light trailers, such as horseboxes and livestock trailers. The new RSA booklet also states that if you need to tow another vehicle using a rope or strap, you should only do so to the nearest safe place of repair. The driver of the towing vehicle must be the holder of a BE driving licence.

The booklet is accompanied by a series of information videos, which are available to view on the RSA’s YouTube page www.youtube.com/rsaireland.