Note: This Rule should be read in conjunction with the Land Transport Rule: Steering Systems Amendment 2009.

Contents

Objective of the rule

Extent of consultation

Part 1     Rule requirements

Section 1     Application

• 1.1     Title
• 1.2     Scope of the rule
• 1.3     Date when rule comes into force
• 1.4     Application of rule provisions

Section 2     Vehicle standards and other safety requirements

• 2.1     Requirements for all motor vehicles
• 2.2     General safety requirements
• 2.3     Approved vehicle standards
• 2.4     Additional requirements for indirect steering systems

Section 3     Modification and repair

• 3.1     Modification
• 3.2     Repair

Section 4     Responsibilities

• 4.1     Responsibilities of operators
• 4.2     Responsibilities of repairers
• 4.3     Responsibilities of modifiers
• 4.4     Responsibilities of certifiers
• 4.5     Responsibilities of manufacturers and retailers

Part 2     Definitions

• Table A:     Vehicle classes

 

Objective of the rule

Land Transport Rule: Steering Systems 2001 is one of a series of rules that sets safety requirements and standards for systems and components in motor vehicles operating in New Zealand. This rule covers the design, construction and maintenance of steering systems in motor vehicles. The rule’s aim is twofold: to ensure that steering systems provide safe and sensitive control of a motor vehicle, and to minimise injury to the driver, who might come into contact with steering systems or components in a crash.

This rule updates and replaces Land Transport Rule: Steering Systems 1997, which came into force on 1 January 1998.

A number of drafting changes have been made to ensure consistency among the land transport rules relating to vehicle standards. The wording of the general safety requirements has been amended to ensure that the rule covers any system or component that affects the directional control of the motor vehicle.

The scope of the rule has been extended to include motor vehicles outside the classes specified in Table A of the rule.

Apart from these changes, the structure and scope of the rule have not changed materially. The general safety requirements, which apply to most motor vehicles, consolidate and, in effect, roll over relevant provisions of the Traffic Regulations 1976 and the Transport (Vehicle Standards) Regulations 1990. The approved vehicle standards apply only to specified classes of motor vehicle, and only to those vehicles manufactured from the dates set out in the rule. The approved vehicle standards are ‘incorporated by reference’ in accordance with section 165 of the Land Transport Act 1998 so that they are effectively part of the rule. A choice of international standards provides flexibility within agreed safety parameters, and enables New Zealand to align with world best practice.

This rule applies throughout the on-road life of a motor vehicle by including requirements for repair, modification and other aspects of continuing compliance. The rule is an essential element of the safety framework governing motor vehicles in New Zealand. It links with, and provides a means of assessment for, Land Transport Rule: Vehicle Standards Compliance 1998, which sets procedures for vehicle certification for registration, in-service fitness and other purposes.

There is a close relationship between this rule and Land Transport Rule: Frontal Impact 2001. Motor vehicles that comply with Land Transport Rule: Frontal Impact 2001 are not required to comply with an approved vehicle standard specified in this rule, although other provisions still apply.

The rule states who is responsible for ensuring compliance with its requirements: operators, repairers, modifiers, certifiers, manufacturers and retailers. This links the rule to relevant provisions of the Land Transport (Offences and Penalties) Regulations 1999 (see in particular regulation 3 in conjunction with Schedule 1).

 

Extent of consultation

Land Transport Rule: Steering Systems 1997 underwent a three-and-a-half-year period of extensive consultation, beginning in March 1994, with industry groups, interested government agencies and the public. The consultation undertaken by the Land Transport Safety Authority (LTSA) included the holding of formal and informal meetings with representatives, interested groups and individuals.

The LTSA has received comments on Land Transport Rule: Steering Systems 1997 as part of its ongoing function of consultation with industry groups affected by vehicle standards in general. These comments have been taken into account in producing Land Transport Rule: Steering Systems 2001.

Formal consultation began on 31 March 1999 with the release of the yellow (public consultation) draft of this revised rule, together with the drafts of several other revised rules for vehicle standards, to about 800 interested organisations and individuals. The availability of the yellow draft was publicised in 15 metropolitan and regional daily newspapers, the New Zealand Gazette, Te Maori News, the Rural Bulletin and industry publications. Copies of the draft rule were sent to overseas libraries and transport authorities. The draft rule was also accessible on the LTSA’s website. The LTSA received four submissions specifically on the yellow draft of this rule. Other submissions related generally to all the revised rules for vehicle standards released at that time.

Issues identified in submissions were taken into account in redrafting this rule before it was submitted to Cabinet, and to the Minister of Transport for signature.

 

Part 1     Rule requirements

Section 1     Application

1.1     Title

This rule is Land Transport Rule: Steering Systems 2001.

 

1.2     Scope of the rule

1.2(1)     This rule applies to the steering systems, and associated systems and components that could directly or indirectly affect the directional control of the vehicle, on all motor vehicles, including vehicles of the classes in Table A in Part 2.

1.2(2)     This rule specifies requirements:

• (a) with which a motor vehicle must comply so as to be operated on a road; and
• (b) that are, for the purposes of Land Transport Rule: Vehicle Standards Compliance 1998, the applicable requirements for steering systems.

 

1.3     Date when rule comes into force

1.3(1)     This rule revokes and replaces Land Transport Rule: Steering Systems 1997, which came into force on 1 January 1998.

1.3(2)     This rule comes into force on 1 April 2002.

 

1.4     Application of rule provisions

1.4(1)     If there is a conflict between a provision of this rule and the corresponding provision of a document incorporated by reference in the rule, the provision of the rule applies.

1.4(2)     If there is a conflict between a provision of this rule and a provision of Land Transport Rule: Vehicle Standards Compliance 1998, the provision of Land Transport Rule: Vehicle Standards Compliance 1998 applies.

 

Section 2     Vehicle standards and other safety requirements

2.1     Requirements for all motor vehicles

2.1(1)     A steering system on a motor vehicle, and associated systems and components that could directly or indirectly affect the directional control of the vehicle, must comply with 2.2.

2.1(2)     A steering system on a motor vehicle must comply with 2.3 if this is specified in Table 2.1 for that vehicle class.

 

2.2     General safety requirements

2.2(1)     The items specified in 2.1 must be sound and in good condition and must provide the vehicle with safe, efficient, convenient and sensitive control.

2.2(2)     The items specified in 2.1 must be strong, durable and fit for their purpose, taking into account whether adverse effects have resulted from a loss of integrity of any protective system used by a relevant component.

 

Table 2.1     Requirements for motor vehicles that are not low volume vehicles

Class	Manufactured before 1 January 1992	Manufactured on or after 1 January 1992 and before 1 March 1998	Manufactured on or after 1 March 1998
MA	General safety requirements	General safety requirements and approved vehicle standard	General safety requirements and approved vehicle standard
MB	General safety requirements	General safety requirements	General safety requirements and on or after 1 March 1999 approved vehicle standard
MC	General safety requirements	General safety requirements	General safety requirements and approved vehicle standard
AB, LA, LB1, LB2, LC, LD, LE1, LE2, MD1, MD2, MD3, MD4, ME, NA, NB, NC, TA, TB, TC, TD	General safety requirements	General safety requirements	General safety requirements
Motor vehicles not in Table A	General safety requirements	General safety requirements	General safety requirements

 

Table 2.2     Requirements for low volume vehicle¹

Class	Light motor vehicle last modified on or after 1 January 1992 and certified as a low volume vehicle
Low volume vehicle	General safety requirements and Low Volume Vehicle Code

Note:
¹ The concept of low volume vehicles and hence certification for such vehicles was not initiated until after 1991. A motor vehicle last modified before 1 January 1992 does not have to comply with the Low Volume Vehicle Code, provided the vehicle has been continuously registered in New Zealand. It must, however, comply with the general safety requirements in 2.2.

 

2.2(3)     In assessing whether an item specified in 2.1 complies with 2.2(1) or 2.2(2), a person specified in section 4 may take into account evidence that it is within the vehicle manufacturer’s operating limits.

 

2.3     Approved vehicle standards

2.3(1)     A steering system must comply, if specified in Table 2.1, with a version, as specified in 2.3(4), of:

• (a) the two approved vehicle standards in 2.3(2)(a); or
• (b) the two approved vehicle standards in 2.3(2)(b); or
• (c) the two approved vehicle standards in 2.3(2)(c); or
• (d) the approved vehicle standard in 2.3(2)(d); or
• (e) the approved vehicle standard in 2.3(2)(e).

2.3(2)     The approved vehicle standards for steering systems are:

• (a) the following:
  • (i) Council Directive of 4 June 1974 on the approximation of the laws of the Member States relating to the interior fittings of motor vehicles (the behaviour of the steering mechanism in the event of an impact) (74/297/EEC); and
  • (ii) Council Directive of 8 June 1970 on the approximation of the laws of the Member States relating to the steering equipment for motor vehicles and their trailers (70/311/EEC);
• (b) the following:
  • (i) UN/ECE Regulation No. 12, Uniform provisions concerning the approval of vehicles with regard to the protection of the driver against the steering mechanism in the event of impact (E/ECE324-E/ECE/TRANS/505/Add.11); and
  • (ii) UN/ECE Regulation No. 79, Uniform provisions concerning the approval of vehicles with regard to steering equipment (E/ECE324-E/ECE/TRANS/505/Rev.1/Add.78);
• (c) the following:
  • (i) Federal Motor Vehicle Safety Standard No. 203, Impact Protection for the Driver from the Steering Control System - Passenger Cars; and
  • (ii) Federal Motor Vehicle Safety Standard No. 204, Steering Control Rearward Displacement - Passenger Cars, Multipurpose Passenger Vehicles, Trucks and Buses;
• (d) Australian Design Rule 10, Steering Column;
• (e) Technical Standard for Steering System Impact (Japan).

 

    Approved vehicle standards include amendments to standards

2.3(3)     An approved vehicle standard in 2.3(2) includes all amendments to that standard, some of which may apply to classes of vehicle additional to those covered by the original standard.

 

    Version of vehicle standards

2.3(4)     A steering system must comply with the version of an approved vehicle standard that is:

• (a) applicable in the relevant standard-setting jurisdiction to the date of manufacture of the motor vehicle or as specified in the standard; or
• (b) a more recent version of that standard if the safety performance of the motor vehicle is not adversely affected.

 

    Compliance with vehicle standards

2.3(5)     A steering system complies for the purpose of this rule with an applicable approved vehicle standard if:

• (a) it complied with that standard when the motor vehicle was manufactured or modified; and
• (b) it is currently within safe tolerance of its state when the motor vehicle was manufactured or modified.

2.3(6)     A steering system and its components that are manufactured, stocked or offered for sale in New Zealand, and are intended for fitting to a motor vehicle to be operated on a New Zealand road, must not prevent the vehicle from complying with one or more of the approved vehicle standards in 2.3(2), unless specifically designed for a vehicle:

• (a) to which a specified standard does not apply for any reason, for example, because of the vehicle’s class or date of manufacture; or
• (b) that is a low volume vehicle.

2.3(7)     A steering system on a low volume vehicle must comply, as specified in Table 2.2, with the requirements of the Low Volume Vehicle Code that are applicable to the date of certification or recertification of the motor vehicle as a low volume vehicle.

2.3(8)     A motor vehicle must comply with an approved vehicle standard in this rule unless:

• (a) that vehicle was manufactured before the phase-in date for the model, or model variant, of that vehicle in the relevant standard-setting jurisdiction or as specified in the standard; or
• (b) the model, or model variant, of that vehicle is not required by that standard itself to comply fully with that standard.

2.3(9)     A motor vehicle does not have to comply with an approved vehicle standard in this rule if the vehicle complies with a version of one of the approved vehicle standards in Land Transport Rule: Frontal Impact 2001, whether or not that vehicle is required by that rule to so comply.

 

2.4     Additional requirements for indirect steering systems

A motor vehicle capable of a speed of more than 30 km/h and equipped with a steering system with no direct mechanical connection between the driver’s means of control and the wheels or other means of changing the vehicle’s direction must have at least one additional means of steering that complies with 2.2.

 

Section 3     Modification and repair

3.1     Modification

3.1(1)     A modification to a steering system, or to a system or component that could affect the directional control of a motor vehicle:

• (a) must not prevent the vehicle from complying with this rule; and
• (b) must be certified as specified in Land Transport Rule: Vehicle Standards Compliance 1998.

3.1(2)     If a steering system, or a system or component that could affect the directional control of a motor vehicle, is modified:

• (a) the steering system must be compatible with the performance and component specifications of the manufacturer of the vehicle or steering system, for the original steering system; and
• (b) the loads and stresses on the steering system and its components must be demonstrably within the design and performance criteria established by their manufacturer for the specific application in which they were originally used.

 

3.2     Repair

A repair to a steering system, or a repair to a motor vehicle that affects its steering system, must comply with this rule and with Land Transport Rule: Vehicle Repair 1998.

 

Section 4     Responsibilities

4.1     Responsibilities of operators

A person who operates a motor vehicle must ensure that the vehicle complies with this rule.

 

4.2     Responsibilities of repairers

A person who repairs or adjusts a steering system, or a motor vehicle so as to affect its steering system, must ensure that the repair or adjustment:

• (a) does not prevent the vehicle from complying with this rule; and
• (b) complies with Land Transport Rule: Vehicle Repair 1998.

 

4.3     Responsibilities of modifiers

A person who modifies a steering system, or a motor vehicle so as to affect the safety performance of its steering system, must:

• (a) ensure that the modification does not prevent the vehicle from complying with this rule; and
• (b) notify the operator if the vehicle must be inspected and, if necessary, certified, because there is reason to believe it is:
  • (i) a light motor vehicle that has been modified to become a low volume vehicle; or
  • (ii) a heavy motor vehicle that has been modified so as to adversely affect its safety performance or compliance with this rule.

 

4.4     Responsibilities of certifiers

A certifier must not certify a motor vehicle under Land Transport Rule: Vehicle Standards Compliance 1998 if they have reason to believe that the vehicle does not comply with this rule.

 

4.5     Responsibilities of manufacturers and retailers

A person may manufacture, stock or offer for sale a steering system, or its components, intended for fitting to a motor vehicle to be operated on a New Zealand road, only if the steering system or its components:

• (a) comply with this rule; and
• (b) does not prevent a repair to a vehicle, its structure, systems, components or equipment from complying with this rule.

[Note: A breach of a responsibility in this section is an offence, as provided in the Land Transport (Offences and Penalties) Regulations 1999, and is subject to a penalty as specified in those regulations.]

 

Part 2     Definitions

Approved vehicle standard

means a vehicle standard in 2.3(2).

Certifier

means a person appointed by the Director in accordance with Land Transport Rule: Vehicle Standards Compliance 1998.

Certify

in relation to a motor vehicle, means to verify that the vehicle complies with applicable requirements.

Class

in relation to vehicles, means a category of vehicle of one of the Groups A, L, M, N and T, as specified in Table A: Vehicle classes.

Director

means the Director of Land Transport Safety appointed under section 186 of the Land Transport Act 1998.

EEC, EC

are abbreviations for directives of the European Economic Community and, later, the European Communities.

Federal Motor Vehicle Safety Standard

is a vehicle standard of the United States of America.

Gross vehicle mass

means either:

• (a) the maximum permitted mass of a vehicle, which includes the mass of the accessories, the crew, the passengers and load, and is, unless (b) applies, the gross vehicle mass specified (subsequent to the latest modification, if any) by the manufacturer of the vehicle; or
• (b) if a person approved for the purpose by the Director determines that the gross vehicle mass should differ from that specified by the manufacturer, taking into account evidence on the capability of the systems and components of the vehicle, or the effects of any modification, that mass determined by that person.

Heavy motor vehicle

means a motor vehicle that is either:

• (a) of Class MD3, MD4, ME, NB, NC, TC or TD; or
• (b) a vehicle (not of a class in Table A: Vehicle classes) with a gross vehicle mass that exceeds 3500 kg.

Light motor vehicle

means a motor vehicle of any class except one defined as a ‘heavy motor vehicle’.

Low volume vehicle

means a motor vehicle of a class in Table A: Vehicle classes, other than Class MD3, MD4, ME, NB, NC, TC or TD, that is:

• (a) manufactured, assembled or scratch-built in quantities of 200 or less at any one location in any one year, by a manufacturer whose total production of motor vehicles does not exceed 200 units over the same period, and where the construction of the vehicle directly or indirectly affects compliance of the vehicle with any of the vehicle standards prescribed by New Zealand law; or
• (b) modified uniquely, or in quantities of 200 or less at any one location in any one year, in such a way as to affect the compliance of the vehicle, its structure, systems, components and equipment, with a legal requirement relating to safety performance applicable at the time of the modification.

 

Low Volume Vehicle Code

means the code of the Low Volume Vehicle Technical Association Incorporated.

Manufacturer’s operating limits

means:

• (a) in relation to a motor vehicle, the allowance provided by the vehicle manufacturer in terms of performance capability and dimensions, relative to deterioration, malfunction or damage beyond which the safe performance of the vehicle, as defined by the vehicle manufacturer, is compromised; and
• (b) in relation to a system, component or item of equipment, incorporated in or attached to a vehicle, the allowance provided by the system, component or equipment manufacturer in terms of performance capability and dimensions, relative to the deterioration, malfunction or damage, beyond which the safe performance of the system, component or item of equipment (and consequently the vehicle) is compromised.

Modify

in relation to a motor vehicle, means to change the vehicle from its original state by altering, substituting, adding or removing any structure, system, component or equipment; but does not include repair.

Motor vehicle

means a vehicle drawn or propelled by mechanical power; and includes a trailer; but does not include:

• (a) a vehicle running on rails;
• (b) an invalid carriage;
• (c) a trailer (other than a trailer designed solely for the carriage of goods) that is designed and used exclusively as part of the armament of the New Zealand Defence Force;
• (d) a trailer running on one wheel and designed exclusively as a speed measuring device or for testing the wear of vehicle tyres;
• (e) a vehicle designed for amusement purposes and used exclusively within a place of recreation, amusement, or entertainment to which the public does not have access with motor vehicles;
• (f) a pedestrian-controlled machine.

Operate

in relation to a vehicle, means to drive or use the vehicle on a road, or to cause or permit the vehicle to be on a road, or to be driven on a road, whether or not the person is present with the vehicle.

Phase-in date

means the date specified in an approved vehicle standard from which a model, or model variant, of a vehicle must comply with that standard or part of that standard.

Repair

means to restore a damaged or worn motor vehicle, its structure, systems, components or equipment; and includes the replacement of damaged or worn structures, systems, components or equipment with equivalent undamaged or new structures, systems, components or equipment.

Safe tolerance

means the tolerance within which the safe performance of the vehicle, its structure, systems, components or equipment is not compromised, having regard to any manufacturer’s operating limits.

Scratch-built vehicle

means a motor vehicle that is either:

• (a) assembled from previously unrelated components and construction materials that have not been predominantly sourced from donors of a single make or model and that, in its completed form, never previously existed as a mass-produced vehicle, although the external appearance may resemble or replicate an existing vehicle; or
• (b) a modified production vehicle that contains less than the following components from a mass-produced vehicle of a single make and model:
  • (i) 40% of the chassis rails and 50% of the crossmembers, or alternatively 40% of a spaceframe, or 40% of the floorpan of a unitary constructed body, whichever is appropriate; or
  • (ii) for light vehicles, 40% of the bodywork (based on surface area of body panels but not including the floorpan, internal bracing, subpanels, bulkheads or firewall).

Steering system

means those components, parts and systems that connect the driver’s controls to the vehicle’s wheels or tracks by means of which the direction of motion of a vehicle is controlled.

Technical Standard

means a Japanese domestic vehicle standard issued by the Japanese Ministry of Land, Infrastructure and Transport and translated into, and published in, English by the Japan Automobile Standards Internationalization Center (JASIC) in the Automobile Type Approval Handbook for Japanese Certification.

UN/ECE

is an abbreviation for a regulation of the United Nations Economic Commission for Europe.

Vehicle standard

means a technical specification with which a motor vehicle, its structure, systems, components or equipment must comply, and which is adopted by:

• (a) the New Zealand Standards Council; or
• (b) any international, national or regional organisation with functions similar to the New Zealand Standards Council.

 

Table A     Vehicle classes

Class	Description
AA (Pedal cycle)	A vehicle designed to be propelled through a mechanism solely by human power.
AB (Power-assisted pedal cycle)	A pedal cycle to which is attached one or more auxiliary propulsion motors having a combined maximum power output not exceeding 200 watts.
LA (Moped with two wheels)	A motor vehicle (other than a power-assisted pedal cycle) that: (a) has two wheels; and (b) either: (i) has an engine cylinder capacity not exceeding 50 ml and a maximum speed not exceeding 50 km/h; or (ii) has a power source other than a piston engine and a maximum speed not exceeding 50 km/h.
LB (Moped with three wheels)	A motor vehicle (other than a power-assisted pedal cycle) that: (a) has three wheels; and (b) either: (i) has an engine cylinder capacity not exceeding 50 ml and a maximum speed not exceeding 50 km/h; or (ii) has a power source other than a piston engine and a maximum speed not exceeding 50 km/h.
LB 1	A Class LB motor vehicle that has one wheel at the front and two wheels at the rear.
LB 2	A Class LB motor vehicle that has two wheels at the front and one wheel at the rear.
LC (Motorcycle)	A motor vehicle that: (a) has two wheels; and (b) either: (i) has an engine cylinder capacity exceeding 50 ml; or (ii) has a maximum speed exceeding 50 km/h.
LD (Motorcycle and side-car)	A motor vehicle that: (a) has three wheels asymmetrically arranged in relation to the longitudinal median axis; and (b) either: (i) has an engine cylinder capacity exceeding 50 ml; or (ii) has a maximum speed exceeding 50 km/h.
Side-car	A car, box, or other receptacle attached to the side of a motor cycle and supported by a wheel.
LE (Motor tri-cycle)	A motor vehicle that: (a) has three wheels symmetrically arranged in relation to the longitudinal median axis; and (b) has a gross vehicle mass not exceeding one tonne; and (c) either: (i) has an engine cylinder capacity exceeding 50 ml; or (ii) has a maximum speed exceeding 50 km/h.
LE 1	A Class LE motor vehicle that has one wheel at the front and two wheels at the rear.
LE 2	A Class LE motor vehicle that has two wheels at the front and one wheel at the rear.
Passenger vehicle	A motor vehicle that: (a) is constructed primarily for the carriage of passengers; and (b) either: (i) has at least four wheels; or (ii) has three wheels and a gross vehicle mass exceeding one tonne.
MA (Passenger car)	A passenger vehicle (other than a Class MB or Class MC vehicle) that has not more than nine seating positions (including the driver's seating position).
MB (Forward control passenger vehicle)	A passenger vehicle (other than a Class MC vehicle): (a) that has not more than nine seating positions (including the driver's seating position); and (b) in which the centre of the steering wheel is in the forward quarter of the vehicle's total length.
MC (Off-road passenger vehicle)	A passenger vehicle, designed with special features for off-road operation, that has not more than nine seating positions (including the driver's seating position), and that: (a) has four-wheel drive; and (b) has at least four of the following characteristics when the vehicle is unladen on a level surface and the front wheels are parallel to the vehicle's longitudinal centre-line and the tyres are inflated to the vehicle manufacturer's recommended pressure: (i) an approach angle of not less than 28 degrees; (ii) a breakover angle of not less than 14 degrees; (iii) a departure angle of not less than 20 degrees; (iv) a running clearance of not less than 200 mm; (v) a front axle clearance, rear axle clearance, or suspension clearance of not less than 175 mm.
Omnibus	A passenger vehicle that has more than nine seating positions (including the driver's seating position). An omnibus comprising two or more non-separable but articulated units shall be considered as a single vehicle.
MD (Light omnibus)	An omnibus that has a gross vehicle mass not exceeding 5 tonnes.
MD 1	An omnibus that has a gross vehicle mass not exceeding 3.5 tonnes and not more than 12 seats.
MD 2	An omnibus that has a gross vehicle mass not exceeding 3.5 tonnes and more than 12 seats.
MD 3	An omnibus that has a gross vehicle mass exceeding 3.5 tonnes but not exceeding 4.5 tonnes.
MD 4	An omnibus that has a gross vehicle mass exceeding 4.5 tonnes but not exceeding 5 tonnes.
ME (Heavy omnibus)	An omnibus that has a gross vehicle mass exceeding 5 tonnes.
Goods vehicle	A motor vehicle that: (a) is constructed primarily for the carriage of goods; and (b) either: (i) has at least four wheels; or (ii) has three wheels and a gross vehicle mass exceeding one tonne. For the purpose of this description: (a) a vehicle that is constructed for both the carriage of goods and passengers shall be considered primarily for the carriage of goods if the number of seating positions multiplied by 68 kg is less than 50% of the difference between the gross vehicle mass and the unladen mass; (b) the equipment and installations carried on special purpose vehicles not designed for the carriage of passengers shall be considered to be goods; (c) a goods vehicle that has two or more non-separable but articulated units shall be considered to be a single vehicle.
NA (Light goods vehicle)	A goods vehicle that has a gross vehicle mass not exceeding 3.5 tonnes.
NB (Medium goods vehicle)	A goods vehicle that has a gross vehicle mass exceeding 3.5 tonnes but not exceeding 12 tonnes.
NC (Heavy goods vehicle)	A goods vehicle that has a gross vehicle mass exceeding 12 tonnes.
Trailer	A vehicle without motive power that is constructed for the purpose of being drawn behind a motor vehicle.
TA (Very light trailer)	A single-axled trailer that has a gross vehicle mass not exceeding 0.75 tonnes.
TB (Light trailer)	A trailer (other than a Class TA trailer) that has a gross vehicle mass not exceeding 3.5 tonnes.
TC (Medium trailer)	A trailer that has a gross vehicle mass exceeding 3.5 tonnes but not exceeding 10 tonnes.
TD (Heavy trailer)	A trailer that has a gross vehicle mass exceeding 10 tonnes.