None of the terms or prohibitions of the foregoing sections of this chapter shall apply to or be enforced against:
(A) Any vehicle of the City while engaged upon necessary public business;
(B) Excavations or repairs of bridges, streets or highways by or on behalf of the City, the county or the state; or
(C) The reasonable use of amplifiers or loudspeakers at public gatherings and in the course of addresses which are non-commercial in character.