General Knowledge · Alcohol, Other Drugs, and Driving
Which of the following is prohibited for a driver who is on duty, under 49 CFR 392.4?
1.Possessing, being under the influence of, or using a Schedule I controlled substance, an amphetamine, a narcotic, or any other substance that renders the driver incapable of safely operating the vehicleCorrect answer
2.Only Schedule I substances are prohibited; prescription amphetamines are always allowed, whatever the dosage the prescribing doctor happened to settle on for the driver
3.The prohibition applies only while the driver is actually behind the wheel and the vehicle is moving, not merely while the driver happens to be on duty somewhere around the carrier's own terminal yard there
4.Only illegal, non-prescription drugs are covered by this rule, so anything that was lawfully prescribed falls outside it entirely, whatever its real effects on the driver
Explanation
A driver on duty may not possess, be under the influence of, or use a Schedule I controlled substance, an amphetamine, a narcotic drug, or any other substance to a degree that renders the driver incapable of safely operating the vehicle, under 49 CFR 392.4. The wrong options each narrow the rule incorrectly: amphetamines are named specifically alongside Schedule I substances, not exempted, the prohibition applies to being on duty generally, not only to moments of active driving, and the "any other substance" clause means the rule is not limited to illegal drugs alone.
Source: 49 CFR 392.4
Related Alcohol, Other Drugs, and Driving questions
- How long before going on duty or operating a commercial motor vehicle must a driver avoid using alcohol or being under its influence?
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