3. All holders of bus transport permits, all school carriers, all public bodies providing public transport within the meaning of the Bus Transport Regulation (chapter T-12, r. 16), all persons who provide transport for handicapped persons covered by category 7 of section 2 of that Regulation, all municipalities, all groupings of municipalities, all intermunicipal management boards and all intermunicipal boards of transport are the carriers to whom paragraph 1 of section 2 refers.