ROAD TRAFFIC AND VEHICLES Citation and commencement 1 These Regulations may be cited as the Motor Vehicles (Authorised Weight) Regulations (Northern Ireland) 1999 and shall come into operation on 20th July 1999. Interpretation 2 1 In these Regulations— “the 1989 Regulations ” means the Motor Vehicles (Construction and Use) Regulations (Northern Ireland) 1989 ; “articulated bus or coach” means a single vehicle which is a bus or coach consisting of 2 or more rigid sections which— articulate relative to one another; are intercommunicating so that passengers can move freely between them; and are permanently connected so that they can only be separated by an operation using facilities normally found only in a workshop; “articulated vehicle” means a tractor unit to which a semi-trailer is attached; “axle weight” means the sum of the weights transmitted to the road surface by all the wheels of an axle, and for the purpose of calculating axle weight the 2 axles comprised in a tandem axle and all the axles comprised in a triaxle shall be treated as one axle; “centre-axle trailer” means a trailer having only a single axle or group of axles which is positioned at or close to the centre of gravity so that, when the trailer is uniformly loaded, the static vertical load transmitted to the towing vehicle does not exceed 10 per cent of the maximum authorised weight for the axle or group of axles or 1000 kg , whichever is the less; “kg” means kilograms; “ m ” means metres; “maximum authorised weight” in relation to a vehicle, vehicle combination or axle means the maximum authorised weight for the vehicle, vehicle combination or axle determined in accordance with these Regulations; “rigid motor vehicle” means a motor vehicle which is not a tractor unit or an articulated bus; “road friendly suspension” means a suspension system whereby at least 75 per cent of the spring effect is produced by air or other compressible fluid under pressure or suspension recognised as being equivalent within the Community as defined in Annex II of Council Directive 96/53 ; “semi-trailer” means a trailer which is constructed or adapted to be drawn by a tractor unit and includes a vehicle which is not itself a motor vehicle but has some or all of its wheels driven by the drawing vehicle; “steering axle” means an axle that can be positively steered by the action of the driver; “tandem axle” means a group of 2 axles not more than 2·5 m apart so linked together that the load applied to one axle is applied to the other; references to a “driving tandem axle” include a tandem axle where either or both the axles comprising the tandem axle are driven and references to a “non-driving tandem axle” are to a tandem axle where neither of the axles comprising it is driven; “tractor unit” means a vehicle by which a trailer partially superimposed on it may be drawn so that, when the trailer is fully loaded, not less than 20 per cent of its load is borne by the drawing vehicle; “triaxle” means— a group of 3 axles in which no axle is more than 3·25 m apart from any other axle; or a group of more than 3 axles in which no axle is more than 4·6 m from any other axle, and in either case so linked together that the load applied to one axle is transferred to both or all the others; and “vehicle combination” means an articulated vehicle or a rigid motor vehicle drawing a trailer. 2 For the purposes of these Regulations the distance between any 2 axles of a vehicle or vehicle combination shall be taken to be the shortest distance between the line joining the centres of the areas of contact with the road surface of the wheels of one axle and the line joining the centres of the areas of contact with the road surface of the wheels of the other axle. Application of Regulations 3 There Regulations apply to all wheeled motor vehicles and trailers which fall within category M 2 , M 3 , N 2 , N 3 , O 3 or O 4 of the vehicle categories defined in Annex II of Directive 70/156/ EEC as substituted by Directive 92/53/ EC except vehicle combinations which for the time being fulfil the requirements of Part II, III or IIIA of Schedule 9A to the 1989 Regulations (exemptions relating to combined transport operations). Maximum authorised weights 4 1 Subject to paragraph (2) and regulation 5, no vehicle to which these Regulations apply and which is of a description specified in a Schedule to these Regulations shall be used on a road if— a the weight of the vehicle exceeds the maximum authorised weight for the vehicle determined in accordance with Schedule 1; b where the vehicle is used as part of a vehicle combination, the weight of the combination exceeds the maximum authorised weight for the combination determined in accordance with Schedule 2; or c the axle weight of any axle of the vehicle exceeds the maximum authorised axle weight for that axle determined in accordance with Schedule 3. 2 A vehicle to which any of the provisions of regulations 73 to 77 of the 1989 Regulations apply, so long as it is so used that those provisions are complied with, shall be taken to comply with these Regulations. Saving for regulation 78 of the 1989 Regulations (over-riding weight restrictions) 5 Nothing in these Regulations shall prejudice or affect regulation 78 of the 1989 Regulations and a person using or permitting a vehicle to be used contrary to the provisions of that regulation commits an offence even if the weights authorised by these Regulations are not exceeded. Sealed with the Official Seal of the Department of the Environment on J. Ritchie Assistant Secretary 8th June 1999.