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.