Road Traffic (Drivers' Ages and Hours of Work) Act 1976

4 Notwithstanding section 38(2) of the [1889 c. 63.] Interpretation Act 1889 (repeals not to affect accrued liabilities and proceedings therefor), no person shall be convicted (whether in proceedings instituted before or in proceedings instituted after the passing of this Act) of an offence under section 4 or any provision of Part III of the principal Act by reason of his having at any time since the beginning of 1976 driven a motor vehicle of any class on a road under the age which by or under the said section 4 is the minimum age for driving a motor vehicle of that class if at that time he was the holder of a driving licence issued before the passing of this Act authorising him to drive a motor vehicle of that class and had attained the minimum age specified in the licence for driving that class of vehicle.