ROAD TRAFFIC Commencement and citation 1 These Regulations shall come into operation on 15th September 1978, and may be cited as the Weighing of Motor Vehicles (Use of Dynamic Axle Weighing Machines) Regulations 1978. Interpretation 2 1 In these Regulations— “ the Act of 1972 ” means the Road Traffic Act 1972 as amended by the Road Traffic Act 1974; “ authorised person ” means a person authorised by a highway authority, or a constable authorised on behalf of a highway authority by a police authority or a chief officer of police, or, to the extent provided for in section 160(4) of the Act of 1972, a certifying officer appointed under Part III of the Road Traffic Act 1960 or an examiner appointed under section 56 of the Act of 1972 or an officer of the Secretary of State authorised by him in that behalf; “ dynamic axle weighing machine ” means a machine for ascertaining separately the weights transmitted to it by the wheels of each axle of a vehicle when the vehicle is in motion as it passes over the weighing platform of the machine. 2 For the purpose of these Regulations any two or more wheels of a vehicle in the same line transversely shall be regarded as wheels of one axle. 3 The Interpretation Act 1889 shall apply for the interpretation of these Regulations as it applies for the interpretation of an Act of Parliament. Manner of weighing or testing weights by means of dynamic axle weighing machines 3 Where a motor vehicle or trailer is to be weighed, or the weight transmitted to the road by any parts of the vehicle or trailer in contact with the road is to be tested, by means of a dynamic axle weighing machine, the weighing or testing shall be effected by causing the motor vehicle to be driven, or the trailer to be drawn, across the weighing platform of the machine in accordance with the instructions of an authorised person in charge of the machine in a manner and at a steady speed appropriate for ensuring that— a the machine can show successively the weight transmitted to it by the wheels of each axle of the vehicle or trailer, and b in a case where the machine does not itself automatically make a printed record of each weight, the authorised person in charge of the machine can record each of the weights shown by the machine as such weights are shown. Limits of presumed accuracy for dynamic axle weighing machines 4 The limits within which, unless the contrary is proved, any weight determined by a dynamic axle weighing machine is to be presumed to be accurate for the purposes of any provision made by or under the Act of 1972 or by or under any other enactment relating to motor vehicles or trailers, are plus or minus 150 kilograms for the wheels of each axle the weight transmitted by which is shown on the machine at any one time and, where the machine also records the sum of the weights transmitted by the wheels of all the axles of a motor vehicle or trailer, plus or minus 150 kilograms multiplied by the number of the axles. Form of certificate of weight 5 In a case where a motor vehicle or trailer is weighed, or the weight transmitted to the road by any parts of the vehicle or trailer in contact with the road is tested, by means of a dynamic axle weighing machine a certificate in the form set out in the Schedule to these Regulations is hereby prescribed for the purposes of subsection (5) of section 160 of the Act of 1972. William Rodgers Secretary of State for Transport 7th August 1978