No motor vehicle shall be driven on a motorway by a person who is authorised to drive that vehicle only by virtue of his being the holder of a provisional licence under section 88(2) of the Road Traffic Act 19727, unless, since the date of coming into force of the said provisional licence that person has passed a test prescribed under section 85 of the Road Traffic Act 1972 sufficient to entitle him under that Act to be granted a licence, other than a provisional licence, authorising him to drive that vehicle on a road.