49 CFR § 390.39 - Exemptions for “covered farm vehicles.”
(a) Federal requirements. A covered farm vehicle, as defined in § 390.5, including the individual operating that vehicle, is exempt from the following:
(1) Any requirement relating to commercial driver's licenses in 49 CFR Part 383 or controlled substances and alcohol use and testing in 49 CFR Part 382;
(2) Any requirement in 49 CFR Part 391, Subpart E, Physical Qualifications and Examinations.
(3) Any requirement in 49 CFR Part 395, Hours of Service of Drivers.
(4) Any requirement in 49 CFR Part 396, Inspection, Repair, and Maintenance.
(b) State requirements—(1) In general. Federal transportation funding to a State may not be terminated, limited, or otherwise interfered with as a result of the State exempting a covered farm vehicle, including the individual operating that vehicle, from—
(i) A requirement described in paragraph (a) of this section; or
(ii) Any other minimum standard provided by a State relating to the operation of that vehicle.
(2) Exception. Paragraph (b)(1) of this section does not apply with respect to a covered farm vehicle transporting hazardous materials that require a placard.
(c) Other exemptions and exceptions. The exemptions in paragraphs (a) and (b) of this section are in addition to, not in place of, the agricultural exemptions and exceptions in §§ 383.3(d)(1), 383.3(e), 383.3(f), 391.2(a), 391.2(b), 391.2(c), 391.67, 395.1(e)(1), 395.1(e)(2), 395.1(h), 395.1(i), and 395.1(k) of this chapter. Motor carriers and drivers may utilize any combination of these exemptions and exceptions, providing they comply fully with each separate exemption and exception.