A-frames and dollies
If you attach an A-frame to a car in order to tow it with a larger vehicle, the car plus A-frame counts as a trailer.
If you use a dolly to tow a broken-down vehicle, the dolly counts as a trailer.
In both cases the usual safety regulations for trailers apply.
Read more in the ‘A’ frames and dollies’ factsheet.
https://www.gov.uk/government/publications/vehicle-safety-standards-information-sheets
September 2011
“A”- Frames
When an "A" frame is attached to a vehicle (e.g. a motor car) and towed by a motor vehicle (e.g.
motorhome) we believe the "A" frame and car become a single unit and as such are classified in
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
Great Britain. 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).
Trailers having a combined axle mass not exceedi
ng 750kg are not required to have brakes fitted.
However, if the trailer (regardless of mass) is fitt
ed with a braking system, then all brakes in that
system must operate correctly.
The regulations do not include design constraints on how this
should be achieved but, for example, it could be met
by direct linking of the trailer brakes to the
brake system of the towing vehicl
e or by automatic inertia (overr
un) operation via the towing hitch.
Inertia systems can only be used for trailers wi
th a maximum combined axle mass of 3500kg.
Regulations 15 and 16 of C&U set out the brak
ing requirements - including minimum braking
efficiencies for trailer brakes. Subject to certai
n age exemptions, the regulat
ion requires the braking
system to comply with the construction,
fitting and performance requirements of European
Community Directive 71/320/EEC along with its va
rious amending Directives. Alternatively the
braking system can comply with the
corresponding UNECE R
egulation No.13.09.
In addition, C&U Regulation 18 requires the braking system to be maintained in good and efficient working order. If the brakes of the towing vehicle
do not directly operate the trailer brakes the use of an inertia (overrun) system is acceptable. If the trailer braking system has power assistance (i.e.
servo or full power) it is likely that this assistance will be required while in motion to meet the required braking efficiencies. This is because once
the vacuum reservoir is depleted it is possible that the brakes will not meet the braking efficiency. To prevent the trailer being used illegally a
remote vacuum pump, powered from the tow vehicle, could be installed to recharge the reservoir,alternatively a source could be made available from the tow vehicle. From 1 October 1988 the inertia braking system was required to allow the trailer to be reversed by the towing vehicle without
imposing a sustained drag and such devices used for this purpose must engage and disengage automatically. This will be very difficult toachieve on an “A” frame using an inertia (overrun) device.
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 maximummass of 1500kg, the drawbar must be prevented from touching the ground and the trailer able toretain some residual steering.
Whilst being towed, trailers are subject to the relevant requirements given in RVLR, including theuse of triangular red reflectors. There wouldbe further requirements for the display of the appropriate number plate, etc.
From the above I hope it is clear that we believethe use of "A" frames to tow cars behind other vehicles is legal provided the braking and lighting requirements are met. However, while this is our understanding of the Regulations, it is only the Courts which can reach a definitive interpretation of the law.