(b) the applicant may, except where he suffers from a disease or disability specified in the Second Schedule, claim to be subjected to a test of his fitness or ability to drive a motor vehicle of a particular construction or design, and, if he passes such test to the satisfaction of the licensing authority and is not otherwise disqualified, the licensing authority shall grant him a 4[ driving licence] to, drive such motor vehicle as the licensing authority may specify in the 1[ driving licence].