http://www.legislation.gov.uk/ukpga/1972/20/section/53/enactedRoad Traffic Act 1972Road traffic offencesVehiclesRoad safetyDriving licencesHeavy goods vehiclesKing's Printer of Acts of Parliament2019-12-02 PART II 53 1 An authorised examiner may test a motor vehicle on a road for the purpose of ascertaining whether the requirements imposed by law as to— a brakes, silencers, steering gear and tyres; b the prevention or reduction of smoke, fumes or vapour; and c lighting equipment and reflectors, are complied with as respects the vehicle, and of bringing to the notice of the driver any failure to comply with those requirements, and for the purpose of testing the vehicle the examiner may drive it; but a vehicle shall not be required to stop for a test except by a constable in uniform. 2 The following persons may act as authorised examiners for the purposes of this section and section 54 of this Act, that is to say, a certifying officer or public service vehicle examiner appointed under Part III of the Road Traffic Act 1960, a person appointed as an examiner under section 56 of this Act, a person appointed to examine and inspect public carriages for the purposes of the Metropolitan Public Carriage Act 1869, a person appointed to act for the purposes of this section by the Secretary of State, and a constable authorised so to act by or under instructions of the chief officer of police. A person appointed as aforesaid shall produce his authority to act for the purposes of this section if required to do so. 3 On the examiner proceeding to test a vehicle under this section, the driver may elect that the test shall be deferred to a time, and carried out at a place, fixed in accordance with Schedule 3 to this Act, and the provisions of that Schedule shall apply accordingly: Provided that— a where it appears to a constable that, by reason of an accident having occurred owing to the presence of the vehicle on a road, it is requisite that a test should be carried out forthwith, he may require it to be so carried out and, if he is not to carry it out himself, may require that the vehicle shall not be taken away until the test has been carried out; and b where in the opinion of a constable the vehicle is apparently so defective that it ought not to be allowed to proceed without a test's being carried out, he may require the test to be carried out forthwith. 4 If a person obstructs an authorised examiner acting under this section, or fails to comply with a requirement of this section or Schedule 3 to this Act, he shall be guilty of an offence. 5 In this section and in Schedule 3 to this Act " test" includes " inspect" or " inspection ", as the case may require, and references to a vehicle include references to a trailer drawn thereby. 1960 c. 16. 1869 c. 115.