Under what circumstances can a cell phone be used while driving airside?

Using a cell phone while driving airside is subject to strict regulations to ensure safety and operational efficiency. The correct answer indicates that a cell phone can be used when parked in a designated area. This means that if a driver has moved their vehicle to a specific location that is designated for parking—and is not in motion or engaged in operational tasks—they are permitted to use their cell phone. The emphasis on being parked in a designated area highlights the importance of minimizing distractions during vehicle operation in busy and potentially hazardous airside conditions.

In contrast, the other options do not align with best practices regarding the use of cell phones airside. Using a cell phone during emergencies is suggestive but does not account for defined protocols that should be followed in those situations. Waiting at a stoplight does not apply on the airside, as there are typically no stoplights like those found on public roads. The idea of using a cell phone whenever necessary could lead to distractions, which increases risk and is not permitted under standard safety regulations. Thus, the designated parking area serves to ensure the safe handling of communications without compromising vehicle operation.