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This publication is available at https://www.gov.uk/government/publications/a-frames-and-dollies/a-frames-and-dollies
The information contained in this document relates solely to the construction requirements for vehicles. Readers should ensure that they are aware of, and comply with, all relevant requirements on other aspects of vehicle use (driver licensing, vehicle excise duty, insurance etc).
What is an A-frame?
An A-frame is a frame (shaped like an A) which is attached to the front of a vehicle (eg a car) to provide an attachment that allows the vehicle to be towed behind another vehicle (eg a motorhome). The department’s view of the legal position in Great Britain (GB) is outlined below.
Type approval of an A-frame
Type approval of most new trailers became compulsory on 29 October 2012. However, the A-frame itself is neither a vehicle nor a trailer, and is therefore outside the scope of type approval.
When an A-frame is attached to a vehicle (eg a motor car) we consider the A-frame and car temporarily become a single unit. When towed by another motor vehicle (eg motorhome) we believe that this single unit is, for the purposes of its construction, treated in GB legislation as a trailer.
As a consequence, the car and A-frame are required to meet the technical requirements for trailers when used on the road in GB. These requirements are contained within the Road Vehicles (Construction and Use) Regulations 1986 (SI 1986/1078) as amended (C&U) and the Road Vehicles Lighting Regulations 1989 (SI 1989/1796) as amended (RVLR).
It is important that the towed vehicle (car and A-frame assembly) braking system complies with the legal requirements. Regulations 15 of C&U set out the technical requirements for the braking systems of motor vehicles, first used on or after 1 April 1983 and for trailers manufactured on or after 1 October 1982. The minimum braking efficiencies, including those applying to the combination of the towing vehicle and the trailer, are set out in Regulation 18.
Subject to certain age exemptions, (the technical requirements for older vehicles are set out in Regulation 16) the regulation requires the braking system to comply with the construction, fitting and performance requirements of European Community Directive 71/320/EEC along with its various amending directives. Alternatively the braking system can comply with the corresponding UNECE Regulation No.13.09. Regulation 86A of C&U, regarding the use of a secondary coupling, also applies.
Trailers having a maximum laden weight not exceeding 750kg are not required to have brakes fitted. However, if the trailer (regardless of mass) is fitted with a braking system, then all brakes in that system must operate correctly and efficiently. This means that the braking systems of small ‘microcars’ (under 750kg in weight) must still operate, even when the vehicle is being towed. Unless the vehicle is broken down, when C&U makes special provision.
Regulation 18 of C&U requires the braking system to be maintained in good and efficient working order. Where a remote device is used to actuate the brake pedal of a trailer (including a car and A-frame assembly), the actuation device must be properly designed to ensure that the braking performance of the towed vehicle is suitably controlled to ensure the safe and stable braking of the vehicle combination (the towing vehicle and the trailer).
Modern vehicles may be equipped with a range of advanced safety features such as advanced emergency braking (AEB), electronic stability control (ESC), regenerative braking etc. These technologies may render the vehicle unsuitable for use with an A-frame.
Since 1 October 1988 inertia braking systems have been required to allow a trailer to be reversed by the towing vehicle without imposing a sustained braking drag. Devices used to fulfil this requirement must engage and disengage automatically. This applies to A-frames that employ inertia overrun technology.
Other provisions from Regulation 15 and Regulation 86A of C&U require the fitting and use of a secondary coupling system in which the trailer is stopped automatically if the main coupling separates whilst the combination is in motion. Alternatively, 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.
Users should consult both the vehicle manufacturer and the manufacturer of the A-frame device to ensure that all the requirements of the regulations can be met.
Whilst being towed, A-frame and car ‘units’ are subject to the relevant requirements (for trailers) given in RVLR, including the use of triangular red reflectors to the rear. There are also requirements for the display of the appropriate number plate on the rear of the towed ‘unit’.
Use of A-frame outside UK
The views expressed above are only applicable for the UK. We understand that these view are not shared in other European countries and we would not recommend use of an A-frame outside the UK without some investigation of the rules that apply in the relevant country. We are unable to comment on, or enter into correspondence on, the situation in other countries as this will be governed by their domestic laws, together with the Vienna Convention.
We would remind users that the views expressed above relate solely to the technical requirements for a motor vehicle when being used with an A-frame. Users should satisfy themselves that they comply with all other aspects of road traffic law that may apply whether the towed vehicle is viewed as a trailer or as a motor vehicle.
Useful sources of legislation
- UK legislation
- C&U (in un-amended form)
- RVLR (in un-amended form)
- European Braking Directive
- UNECE Regulation 13 and its amendments
The information in this document is a summary of the department’s understanding of what the law requires. However, ultimately the interpretation of the law is a matter for the courts based on individual facts of any particular case. You are therefore advised to consult the relevant legislation and, if necessary, seek independent advice.