3(1)An existing heavy goods vehicle licence issued as a provisional licence, or an existing full heavy goods vehicle licence held by a person under the age of 21, is subject to the prescribed conditions, and if the holder of the licence fails, without reasonable excuse, to comply with any of the conditions he is guilty of an offence.
(2)It is an offence for a person knowingly to cause or permit another person who is under the age of 21 to drive a heavy goods vehicle of any class in contravention of any prescribed conditions to which that other person’s licence is subject.