49 CFR 392.4: Drugs and other substances

What the cited provisions say

Section 392.4(a)(1) prohibits an on-duty driver from possessing, using, or being under the influence of a substance in 21 CFR 1308.11 Schedule I; under § 392.4(d), possession excludes a substance manifested and transported as part of a shipment. Section 392.4(a)(2) addresses an amphetamine or any formulation of it, and § 392.4(a)(3) addresses a narcotic drug or any derivative. Section 392.4(a)(4) addresses any other substance to a degree that renders the driver incapable of safely operating a motor vehicle.^{[1][2][3][4][5]}

Section 392.4(b) places a corresponding obligation on the motor carrier: it must not require or permit a driver to violate § 392.4(a). Section 392.4(c) qualifies possession and use under § 392.4(a)(2), (3), and (4) when the stated medical conditions are satisfied. Section 392.4(d) also limits the possession component by excluding a substance manifested and transported as part of a shipment.^{[1][2][3][4][5]}

Who and what the provisions cover

Section 390.3T(a)(1) applies the subchapter to employers, employees, and commercial motor vehicles transporting property or passengers in interstate commerce, subject to the exceptions in § 390.3T(f). Section 392.1(a) requires every motor carrier and its officers, agents, representatives, and employees responsible for managing, maintaining, operating, or driving commercial motor vehicles, or hiring, supervising, training, assigning, or dispatching drivers, to be instructed in and comply with the rules in part 392. Section 392.1(b) excludes drivers of pipeline welding trucks as defined in the unsaved § 390.38(b).^{[1][2][3][4][5]}

Section 390.5T defines a driver as a person operating a commercial motor vehicle. Its motor carrier definition includes for-hire and private carriers, specified representatives and employees, employers, and exempt motor carriers. Under § 390.5T, a commercial motor vehicle must serve highway transportation in interstate commerce and satisfy a listed criterion: the greater applicable weight or weight rating of 4,536 kg (10,001 pounds) or more; design or use for more than 8 passengers including the driver for compensation; design or use for more than 15 passengers including the driver without compensation; or transportation of designated hazardous material in a quantity requiring placarding.^{[1][2][3][4][5]}

Conditions and exceptions

Section 392.4(c) applies only to possession or use under § 392.4(a)(2), (3), and (4), not the Schedule I category or being under the influence. For possession or use under § 392.4(a)(2), (3), and (4), § 392.4(c) requires the substance to be administered to the driver by or under the instructions of a licensed medical practitioner as defined in § 382.107, who has advised the driver that the substance will not affect the driver's ability to safely operate a motor vehicle. The definition referenced by § 392.4(c) was not supplied.^{[1][2][3][4][5]}

Unless otherwise specifically provided, § 390.3T(f)(1) excludes school bus operations as defined in § 390.5T, while retaining §§ 391.15(e) and (f), 392.15, 392.80, and 392.82. Unless otherwise specifically provided, § 390.3T(f)(2) excludes from the subchapter's rules transportation performed by the Federal government, a State, a political subdivision of a State, or an agency established under a congressionally approved interstate compact. Unless otherwise specifically provided, § 390.3T(f)(3) excludes from the subchapter's rules occasional transportation of personal property by individuals neither for compensation nor in furtherance of a commercial enterprise. Unless otherwise specifically provided, § 390.3T(f)(4) excludes transportation of human corpses or sick and injured persons from the subchapter's rules, and § 390.3T(f)(5) excludes operation of fire trucks and rescue vehicles while involved in emergency and related operations.^{[1][2][3][4][5]}

Unless otherwise specifically provided, § 390.3T(f)(6) excludes operation of commercial motor vehicles designed or used to transport between 9 and 15 passengers, including the driver, not for direct compensation, provided the vehicle does not otherwise meet the commercial motor vehicle definition; motor carriers and drivers operating those vehicles must nevertheless comply with §§ 390.15, 390.19T, 390.21T(a) and (b)(2), 391.15(e) and (f), 392.80, and 392.82. Unless otherwise specifically provided, § 390.3T(f)(7) excludes from the subchapter's rules a driver of a commercial motor vehicle used primarily to transport propane winter heating fuel or a driver of a motor vehicle used to respond to a pipeline emergency, if those regulations would prevent the driver from responding to an emergency condition requiring immediate response as defined in § 390.5T.^{[1][2][3][4][5]}

Related provisions in the saved sources

Section 392.2 requires commercial motor vehicle operation to comply with the laws, ordinances, and regulations of the operating jurisdiction. When an applicable Federal Motor Carrier Safety Administration regulation imposes a higher standard of care, § 392.2 requires compliance with that federal regulation. Section 390.3T(d) permits employers to require and enforce more stringent requirements concerning operational safety and employee safety and health.^{[1][2][3][4][5]}

Section 390.3T(e)(1) requires every employer to know and comply with regulations contained in this subchapter that apply to that motor carrier's operations, while § 390.3T(e)(2) requires every driver and employee to be instructed regarding and comply with all applicable regulations contained in this subchapter. Section 390.3T(e)(3) requires equipment and accessories mandated by the subchapter to remain compliant with applicable performance and design criteria. The saved § 390.5T motor vehicle definition covers mechanically propelled or drawn highway transportation vehicles, while excluding exclusively rail-operated vehicles and qualifying overhead-wire trolley buses furnishing local passenger transportation similar to street-railway service.^{[1][2][3][4][5]}

Source date and limits

The saved-source date is 2026-11-06. This entry uses only the supplied eCFR units attributed to the National Archives and Records Administration, Office of the Federal Register. Its statute-only scope is limited here to the saved federal regulatory text. It does not incorporate judicial interpretation, later amendments, or a verification of the law on the reading date.^{[1][2][3][4][5]}

The source note accompanying § 392.4 records Federal Register publication and amendment references; it does not supply a separate effective-date rule. The Schedule I reference in § 392.4(a)(1) is not reproduced as a substance list. The school bus and emergency-condition definitions referenced in § 390.3T(f) are also absent from the saved definition units. Those omissions limit what this entry can explain without additional authority. This is general reference information about the saved drug and substance provisions, not legal advice or an assessment of a particular driver's circumstances.^{[1][2][3][4][5]}

See also

• FMCSA and federal trucking rules

On related publications

• Texas truck accident statistics (2020-2024) (truckaccidentlawyers.wiki)
• Georgia DPS adoption of federal motor carrier safety rules (atlantatruckaccidentlawyers.wiki)
• https://flanaganlaw.wiki/practice-areas/truck-accidents/ (flanaganlaw.wiki)