(1) The powers conferred on an authorised officer by section 16(1) and 16(2) of the Principal Act are hereby extended -

(a) to include power to inspect any part of a vehicle or combination of vehicles for the purpose of forming an opinion as to whether or not the appropriate regulations under sections 11 and 12 of that Act have been or are being complied with, and

(b) to include power to require the person in charge of a vehicle or combination of vehicles not to proceed further in the vehicle or combination if and so long as -

(i) the vehicle or combination having been weighed in accordance with the said section 16, there is, in the opinion of the officer, a contravention of section 12(3) of the Principal Act in relation to that vehicle or combination, or

(ii) the authorised officer is of opinion that the vehicle or combination does not comply with a regulation under section 11 or 12 of the Principal Act and would, if permitted to proceed further, be likely to cause damage to a public road.

(2) A member of the Garda Síochána may arrest without warrant a person who has refused or failed to comply with a requirement mentioned in subsection (1)(b)(ii).