49 CFR 390.3
(a) The rules in Subchapter B of this chapter are applicable to all employers, employees, and commercial motor vehicles, which transport property or passengers in interstate commerce.
(b) The rules in Part 383, Commercial Driver's License Standards; Requirements and Penalties, are applicable to every person who operates a commercial motor vehicle, as defined in 383.5 of this subchapter, in interstate or intrastate commerce and to all employers of such persons.
(c) The rules in Part 387, Minimum levels of financial responsibility for motor carriers, are applicable to motor carriers as provided in 387.3 or 387.27 of this subchapter.
(d) Nothing in Subchapter B of this chapter shall be construed to prohibit an employer from requiring and enforcing more stringent requirements relating to safety of operation and employee safety and health.
(e)(1) Every employer shall be knowledgeable of and comply with all regulations contained in this subchapter which are applicable to that motor carrier's operations.
(e)(2) Every driver and employee shall be instructed regarding, and shall comply with, all applicable regulations contained in this subchapter.
(e)(3) All motor vehicle equipment and accessories required by this subchapter shall be maintained in compliance with all applicable performance and design criteria set forth in this subchapter.
(f) Unless otherwise specifically provided, the rules in this subchapter do not apply to --
(f)(1) All school bus operations as defined in 390.5;
(f)(2) Transportation performed by the Federal government, a State, or any political subdivision of a State, or an agency established under a compact between States that has been approved by the Congress of the United States;
(f)(3) The occasional transportation of personal property by individuals not for compensation nor in the furtherance of a commercial enterprise;
(f)(4) The transportation of human corpses or sick and injured persons;
(f)(5) The operation of fire trucks and rescue vehicles while involved in emergency and related operations.
(f)(6) The operation of commercial motor vehicles designed to transport less than 16 passengers (including the driver) until March 6, 2000.
[53 FR 18052, May 19, 1988, as amended at 54 FR 12202, Mar. 24, 1989; 58 FR 33776, June 21, 1993; 59 FR 8752, Feb. 23, 1994; 59 FR 67554, Dec. 29, 1994; 62 FR 1293, Jan. 9, 1997; 63 FR 33276, June 18, 1998; 64 FR 48516, September 3, 1999].