The Director of Finance shall revoke a taxicab license under the following circumstances:
(a) Whenever the owner of a taxicab for a period of ninety consecutive days fails to make a reasonable effort to operate any licensed taxicab, after a hearing before the Director;
(b) Whenever the owner of a taxicab permits the operation of the taxicab by a driver who is not licensed in accordance with the terms of this chapter;
(c) Whenever any owner fails to comply with any reasonable rules and regulations established by the Director;
(d) Whenever the owner is convicted by any court of competent jurisdiction of a violation of any of the ordinances of the City, or of the laws of the State, relating to motor vehicles, their operation and equipment, or is convicted by the court of a violation of the national or State laws or ordinances of the City, relating to illegal traffic in intoxicating liquor.
(1984 Code Sec. 117.21)