An aerial lift truck shall not be moved when the boom is elevated in a working position with ___________________.

The requirement that an aerial lift truck should not be moved when the boom is elevated in a working position with personnel in the basket emphasizes safety protocols crucial for preventing accidents. When workers are in the basket, there is an increased risk of injury or fatality if the aerial lift is moved. This risk arises because moving the boom while it is occupied can cause instability, potentially leading to tipping or abrupt movements that could harm workers.

In contrast, operating the lift with the wheels unlocked or with an excess load does not specifically address the inherent dangers of having personnel in the basket during relocation. Unlocking the wheels and excess loads present their own safety concerns, but the priority in this scenario is protecting the safety of workers who are in a vulnerable position within the lift. Therefore, the presence of personnel in the basket is the critical factor that necessitates keeping the aerial lift stationary until it is safe to move.