Which of the following is prohibited for bus drivers while passengers are aboard?

Federal rules prohibit certain operations while passengers are aboard. Fueling with passengers aboard is prohibited except in emergencies where the passengers cannot safely exit; the fueling-while-loaded restriction reflects the risk of vapor exposure, fire, and the difficulty of evacuating a fueled bus on fire. Towing or pushing a disabled vehicle with passengers aboard is also prohibited in most circumstances. Other prohibited practices: smoking by anyone in the bus while passengers are aboard; following another commercial vehicle dangerously close; certain types of cargo carriage. The general principle is that the safety of passengers takes priority over operational convenience.