Introduction
Construction and Use Regulations set out the maximum Length, Width and Height of motor vehicles. The exemptions to these requirements are also noted below and in cases where exceeding these dimensions is the case, the factor that dictates this concerns abnormal loads which is dealt with under STGO (Road Vehicles (Authorisation of Special Types) (General) Order 2003), which can be accessed in the Abnormal Load Section.

Overall Length of Vehicle
Regulation 7 Road Vehicles (Construction and Use) Regulations 1986 states that the overall length of a vehicle or combination of vehicles shall not exceed the maximum length specified below.

Motor vehicles

  • wheeled motor vehicles other than buses – 12 metres,
  • a bus with two axles – 13.5 metres, a bus with more than 2 axles – 15 metres (from 01/04/2003)
  • tracked motor vehicles – 9.2 metres,

Trailers (see Note 1 below)

  • drawbar trailer with at least 4 wheels drawn by goods vehicle over 3500kg gross – 12 metres
  • agricultural trailer with at least 4 wheels – 12 metres
  • semi-trailer (except a car transporter or a semi-trailer which is normally used on international journeys any part of which takes place outside the United Kingdom) – 12.2 metres (see Note 4 below)
  • composite trailer drawn by a goods vehicle over 3500kg gvw. or agricultural motor vehicle – 14.04 metres
  • agricultural trailed appliance manufactured on or after 1st December 1985 – 15 metres including drawbar,
  • any other trailer – 7 metres

Combinations

  • motor vehicle + 1 drawbar trailer 2 – 18.75 metres (see Note 3 below)
  • showman’s motor vehicle + 1 drawbar trailer where the trailer is living accommodation – 22 metres
  • motor vehicle + 2 trailers – 25.9 metres (motor vehicle 9.2 metres max, only one trailer may exceed 7 metres),
  • motor vehicle + 3 trailers – 25.9 metres (motor vehicle 9.2 metres max, no trailer may exceed 7 metres),
  • articulated bus and a bus drawing a trailer – 18.75 metres (from 1/4/2003)
  • articulated vehicle + semi-trailer (see Note 2 below) – 15.5 metres, (see Note 4 below)
  • articulated vehicle + semi-trailer which is a low-loader manufactured on or after 01/04/91 – 18 metres. (see Note 1 below)

Note 1 – Except trailers and combinations including trailers constructed and normally used for abnormal length loads or plant trailers for road construction.

Note 2 – Except combinations involving towing broken down vehicles or trailers constructed and normally used for abnormal length loads.

Note 3 – If motor vehicle manufactured before 1st June 1998 – 18 metres unless certain conditions apply – until 31/12/2006.

Note 4 – Up to 14.04 metres trailer or 16.5 metres combination (16.69 metres for car-transporters) if semi-trailer meets turning circle requirements (Regulations 13A or 13B).

Maximum permitted length
the following covers the relevant vehicle type and its maximum permitted length.

Rigid Vehicle

12 metres

Articulated Vehicle

16.5 metres

(No set limit if designed to carry indivisible loads of exceptional length)

Articulated vehicle

18.0 metres

With a low loader semi-trailer manufacturered on or after 1st April 1991 (excluding step-frame low loaders)

Car Transporter semi-trailer
Kingpin to rear – 12.5 metres
Kingpin to any point on the front – 4.19 metres

Other Semi-trailers

12 metres

Kingpin to rear – 2.04 metres
Kingpin to any point on the front
(These dimensions include the thickness of any front or rear wall. If there is more than one kingpin position the measurement is taken from the rearmost position on semi-trailers manufactured before 1 January 1999, and from the foremost position if manufactured on or after 1 January 1999.)

Composite Trailer

14.04 metres

Drawbar Trailer

12 metres

(Excluding length of drawbar) provided:

The trailer has FOUR or more wheels and the drawing vehicle has a maximum gross weight over 3,500 kgs.
(No set limit if designed to carry indivisible loads of exceptional length).

Other Drawbar trailers

(Excluding length of the drawbar)

7 metres

Road-Train:
One trailer – 18.75 metres
(The distance from the foremost part of the loading area behind the cab to the rear of the trailer must not exceed 16.4 metres and this distance – less the distance between the vehicle and trailer – must not exceed 15.65 metres (this is the maximum length of the load carrying space).
The registration of new road trains with a load space length exceeding 15.65 metres was precluded under EU directive 96/53 with effect from 1 June 1998. The use of pre 1 June 1998 road trains with a load space length exceeding 15.65 metres was prohibited from 31 December 2006.)

Road Train – Two trailers

25.9 metres

(Vehicle drawing more than one trailer is limited to 9.2 metres.)

Other Considerations
Account must be taken of any part of the vehicle, including any permanent receptacle strong enough for repeated use, and fittings on or attached to the vehicle, with the following exceptions;

  • sheeting
  • an empty receptacle which is itself the load**
  • a receptacle containing an indivisible load
  • a receptacle not over 2.5 metres in length or width
  • lifting lugs for multi-modal transport
  • tailboards let down to facilitate carriage but not essential to support loads extending beyond the rearmost point of the vehicle
  • bridging plates on vehicles with trailers, used to facilitate loading and unloading of vehicles carried but not to support them
  • receptacles, other than maritime containers, manufactured before 30 October 1985 (this legalised certain existing demountable bodies)
  • cranes, etc that do not increase the vehicle’s carrying capacity and are a permanent or essentially permanent fixture.

** The regulations define ‘removable superstructure and standardised freight items such as containers’ as being included in the vehicle dimensions regardless of whether or not they are empty. (Directive 96/53/EC Annex 1 1.4.)

Overall Width of Vehicle
Regulation 8 Road Vehicles (Construction and Use) Regulations 1986. The overall width of a vehicle specified below shall not exceed.

Motor vehicles

  • a locomotive, other than an agricultural motor vehicle – 2.75 metres
  • a refrigerated vehicle – 2.60 metres
  • any other motor vehicle – 2.55 metres

Trailers

  • a refrigerated vehicle – 2.60 metres
  • a trailer (any weight) drawn by a motor vehicle which exceeds 3500 kg maximum gross weight – 2.55 metres
  • an agricultural trailer – 2.55 metres
  • an agricultural trailed appliance – 2.55 metres
  • a trailer drawn by a motor cycle (3 wheeled or 2 wheeled with sidecar) – 1.50 metres
  • a trailer drawn by a two wheeled solo motor cycle – 1.00 metres (Regulation 84)
  • any other trailer – 2.30 metres

Other Trailers

  • a broken down vehicle which is being drawn in consequence of the breakdown
  • a wheeled agricultural motor vehicle drawing an offset wheeled trailer is treated as one vehicle for width measurement purposes – maximum width 2.55 metres

Refrigerated vehicles are specially designed for the carriage of goods at low temperature with sidewalls, including insulation, at least 45 mm thick. This regulation deals only with the actual width of a vehicle not the load. Items such as mirrors are not included when measuring the overall width of a vehicle.

Overall Height of Vehicle
Regulation 9 Road Vehicles (Construction and Use) Regulations 1986 A bus shall not exceed 4.57 metres (15′ 0″) overall height. No other type of vehicle is restricted.

Height Plates
Regulation 10 Road Vehicles (Construction and Use) Regulations 1986.

If the overall travelling height of a motor vehicle or its trailer, including load, exceeds 3 metres (9 foot 10 inches), (4 metres if an EC registered vehicle on an international journey), a notice clearly indicating the height in feet and inches (in characters at least 40 millimetres tall) must be displayed in the cab so that it can be clearly read by the driver, indicating:

  • not less than actual overall travelling height or more than 150 millimetres (6 inches) greater, or
  • if high level equipment (hydraulic arms etc.) is fitted, the height at which a warning device would give a visible warning to the driver if exceeded – alarm must set to activate within 1 metre of overall travelling height

Height Plate Exemptions

Where it is highly unlikely that the driver would encounter any bridge or other overhead structure which is less than 1 metre higher than the overall travelling height or the maximum height of high-level equipment when fully extended, allowing for unforeseen diversions or the driver getting lost.

Where document(s) are within easy reach of the driver describing:


a. his route(s) without risk of colliding with any bridge or overhead structure providing the driver is on that route or is off that route because of an unforeseen diversion, or


b. which bridges and structures his vehicle/load could safely pass under and those he could not which are on his route, allowing for unforeseen diversions or the driver getting lost

Height Warning Devices
Regulations 10A and 10B Road Vehicles (Construction and Use) Regulations 1986.

A warning device, which gives a visible warning to the driver if a set height is exceeded, is required on the motor vehicle if high level equipment which exceeds 3 metre when extended, (4 metre if an EC registered vehicle on an international journey), is fitted to a motor vehicle 1st used on/after 01/04/93 or a trailer manufactured on/after 01/04/93.

Exceptions include:

  • agricultural vehicles,
  • industrial tractors,
  • tippers 1st used/manufactured before 1/4/98 in relation to the tipping part,
  • works trucks and works trailers,
  • vehicles owned by or under orders of armed forces,
  • car transporters,
  • fire brigade vehicles,
  • towed broken down vehicles and vehicles where the equipment height (fully extended) does not exceed the vehicle height or where the high level equipment is fitted with a locking device, or where 1 Above applies in relation to the maximum height

Turning Circle

Articulated vehicles with an overall length exceeding 15.5 metres; articulated vehicles with an overall length of 15.5 metres or less where both the tractor and semi-trailer were first used after 31 May 1998 and all goods vehicles defined as heavy motor cars were first used after 31 May 1998 must be able to turn within concentric circles with radii of 12.5 metres and 5.3 metres.


A concession is allowed for car transporters so that any protrusion of the forepeak (for instance any part of the trailer forward of the kingpin) will be ignored.

The following vehicles are exempt;

  • any vehicle with an overall length not over 15.5 metres and first used before 31 May 1998
  • an articulated vehicle, the semi-trailer of which was manufactured before 1 April 1990 (and which has not been modified to increase its length since then)
  • a low loader – defined as a semi-trailer normally used to carry engineering equipment and constructed so that the major part of the load platform does not extend over or between the wheels and the upper surface is below the top of the tyres
  • a vehicle constructed and normally used for exceptionally long indivisible loads
  • a step frame low loader – defined as a semi-trailer (not a low loader) constructed and normally used for engineering equipment and constructed so that the upper surface of the major part of the load platform is less than one metre above the ground
  • a vehicle having four or more axles where the distance between the foremost and rearmost axles exceeds 6.4 metres

Vehicles first used from 1 June 1998, which are fitted with a lift axle, must now meet the turning circle requirements both with and without all the wheels in contact with the ground.

An articulated vehicle is deemed to meet the turning circle requirement if the distance from the kingpin (or front kingpin) to the centre line of the non-steering bogie does not exceed 8.135 metres for a 2.55 metre wide vehicle.

Overhang
Maximum permitted overhang of the body beyond the wheelbase for cars and heavy motor cars, is equal to either 60 per cent of the wheelbase, or the maximum distance the rear of the vehicle may swing out when pulling away from a stationary position on a 12.5 metre radius is 0.8 metres or l metre for lift axles in an unladen condition.


In the case of a two-axled vehicle, or a three-axled vehicle with only one non-steering axle, the overhang is measured from the centre line of the rear axle.


In the case of a three-axled or four-axled vehicle with two non-steering axles, overhang is measured from a point 110 millimetres to the rear of a point midway between the centres of the two rearmost axles. The wheelbase is measured from the centre of the front axle to the point from which overhang is measured.

Case law has indicated that a demountable body or container, which can be lifted on and off a vehicle, is not a load but part of the vehicle and has to be included when calculating the vehicle’s overhang.

Works trucks and certain specialised local authority vehicles are exempt as are tipper vehicles if the overhang does not exceed 1.15 metres. The overhang for a motor tractor must not exceed 1.83 metres.