When must a commercial bus driver use the installed driver’s seat belt?
Correct answer: B – Whenever operating the bus
Federal motor carrier rules prohibit operating a commercial motor vehicle with an installed driver’s seat belt unless the driver is properly restrained. The requirement applies whenever the driver operates the bus, not merely on highways or in heavy traffic. The South Carolina CDL manual also instructs bus drivers to use the seat belt at all times for safety.
Source: South Carolina Commercial Driver’s License Manual — § 4.1.5, “Use Your Seatbelt!”, 49 CFR § 392.16(a) – Use of seat belts

