The Motor Carrier Act shall not apply to:
A. school buses, provided that school buses shall be subject to applicable school bus safety provisions established by the state transportation director;
B. United States mail carriers, unless they are engaged in other business as motor carriers of persons or household goods;
C. hearses, funeral coaches or other motor vehicles belonging to or operated in connection with the business of a funeral service practitioner licensed by the state;
D. a county or municipal public bus transportation system;
E. private carriers; or
F. commuter services.