Section 397.1 - Application of the rules in this part(a) The rules in this part apply to each motor carrier engaged in the transportation of hazardous materials by a motor vehicle which must be marked or placarded in accordance with §177.823 of this title and to- (1) Each officer or employee of the motor carrier who performs supervisory duties related to the transportation of hazardous materials; and(2) Each person who operates or who is in charge of a motor vehicle containing hazardous materials.(b) Each person designated in paragraph (a) of this section must know and obey the rules in this part.36 FR 4876, 3/13/1971, as amended at 36 FR 16067, 8/19/1971; 53 FR 18058, 5/19/1988; 60 FR 38749, 7/28/1995