No person shall be issued a taxicab driver's license unless such person:
(a) Is eighteen years of age or over, a citizen of the United States and of good moral character;
(b) Is of sound physique, with good eyesight, and no bodily or mental infirmities which render him unfit for the safe operation of a motor vehicle;
(c) Is clean in dress and person and not addicted to the use of intoxicating liquors or drugs; and
(d) Undergoes an annual physical examination by a licensed doctor and supplies the Police Chief with a copy of the examination report.