Before weighing a vehicle with bogie axles, what must be done concerning passengers?

For accurate weighing of a vehicle equipped with bogie axles, it's essential that the weight measurement reflects only the vehicle's mass without any additional variables that could skew the results. When passengers remain inside the vehicle during weighing, it can lead to an inaccurate reading due to additional weight that is not part of the vehicle's design specifications. By requiring passengers to exit the vehicle, the measurement obtained is a true representation of the vehicle's weight alone, which is crucial for various applications, including compliance with weight regulations, ensuring balance, and maintaining safety standards.

In contrast, options suggesting that passengers should stay inside or buckle their seat belts do not contribute to achieving an accurate weight measurement and could potentially complicate or misrepresent the results. Thus, having passengers exit is a standard procedure for accurate and reliable measurements.