(1) A person who is guilty of an offence under section 11 or 12 of the Act of 1968 shall be liable on summary conviction to a fine not exceeding €2,000 or, at the discretion of the court, to imprisonment for any term not exceeding three months or to both such fine and such imprisonment.

(2) The following subsection is hereby substituted for subsection (1) of section 13 of the Act of 1968:

"(1) This section applies to every person who owns or operates not less than the prescribed number of mechanically propelled vehicles (being vehicles exceeding 2,000 kilograms in weight unladen and used in public places) and is designated for the purposes of this section in regulations made thereunder.".

(3) The following subsection is hereby substituted for subsection (1) of section 15 of the Act of 1968:

"(1) Where -

(a) a vehicle exceeding 17,000 kilograms in weight laden (within the meaning of the relevant regulations), or a combination of vehicles of which such a vehicle forms a part, is used on a public road,

(b) the owner is convicted of an offence under section 12 of the Principal Act in respect of such use, and

(c) the excess weight during such use was not less than 1,000 kilograms,