With riders aboard, you may not fuel your bus where?

• A. In a parking garage
• B. In a loading dock
• C. In a residential street
• D. In a closed building

Answer: (D)

Fueling with riders aboard is all about preventing fire or explosion from fuel vapors. Gasoline and diesel give off vapors that can ignite if there’s a spark, heat, or static discharge, and you want those vapors to disperse away from the vehicle and people. An enclosed space — a closed building — traps those vapors, allowing them to accumulate to dangerous levels. In that situation, even a small spark could ignite the vapors, posing a serious risk to everyone nearby, including passengers. That’s why fueling in a closed building is prohibited and the safest choice is to fuel outdoors in a well-ventilated area away from ignition sources. The other locations described involve more open airflow or are not designated fueling areas, but the primary danger here is the lack of ventilation in a closed space.