Except for trains or equipment stopped due to mechanical failure where separation or movement is not possible, any train or equipment that has come to a complete stop and is blocking a railroad-highway grade crossing must be cut, separated, or moved to clear the crossing upon the approach of any emergency vehicle, which for the purpose of this law shall be:(1) An ambulance operated by public authority or by private persons;
(2) A fire engine; or an emergency vehicle operated by power or electric companies; or
(3) Any other vehicle when operated as an emergency vehicle, defined as one which is engaged in the saving of life, property, or responding to any other public peril; or
(4) Emergency vehicles used as such by the Government of the United States; when upon the approach of such emergency vehicle, such vehicle gives due warning of its approach to such crossing by the sounding of sirens, flashing of lights, waving of flag, or any other warning sufficient to attract attention to such emergency vehicle; and thereupon the said train or equipment shall be cut and said crossing shall be cleared with all possible dispatch to permit the crossing and passing through of said emergency vehicle.
