The following are exempted from the provisions of this chapter:
The occasional use of a privately and/or publicly owned vehicle not ordinarily used in the business of transporting persons who are sick, injured, wounded, or otherwise incapacitated or helpless, or operating in the performance of a lifesaving act.
A vehicle rendering services as an ambulance in case of a major catastrophe or emergency.
Vehicles owned and operated by rescue squads chartered by the state as corporations not for profit or otherwise existing as nonprofit associations which are not regularly used to transport sick, injured or otherwise incapacitated or helpless persons except as a part of rescue operations.
Ambulances owned and operated by an agency of the United States Government.