Accident means -
(1) Except as provided in paragraph (2) of this definition, an occurrence involving a commercial motor vehicle operating on a highway in interstate or intrastate commerce which results in:
(i) A fatality;
(ii) Bodily injury to a person who, as a result of the injury, immediately receives medical treatment away from the scene of the accident; or
(iii) One or more motor vehicles incurring disabling damage as a result of the accident, requiring the motor vehicle(s) to be transported away from the scene by a tow truck or other motor vehicle.
(2) The term accident does not include:
(i) An occurrence involving only boarding and alighting from a stationary motor vehicle; or
(ii) An occurrence involving only the loading or unloading of cargo.
49 CFR § 390.5
Unless specifically defined elsewhere, in this subchapter: