If a double-deck lorry has the top deck loaded and the lower deck empty, what is the potential risk?

If a double-deck lorry has the top deck loaded and the lower deck empty, what is the potential risk?

• A. You'll need to change gear more often
• B. The lorry may overturn when cornering
• C. The brakes will be less effective
• D. The lorry will become unstable under normal braking

Answer: (B)

High centre of gravity makes a vehicle more likely to roll over in a turn. When the top deck is loaded and the lower deck is empty, most of the weight sits higher above the axles, raising the centre of gravity. As you corner, lateral forces push the vehicle to lean outward; with a high CG, the roll moment is larger and the outer wheels can lift more easily, risking a rollover. The stability provided by a low, broad load isn’t present here, so the main hazard is overturning during cornering. Braking or gear choices aren’t the primary issue in this loading scenario, so the risk isn’t about brakes’ effectiveness.

High centre of gravity makes a vehicle more likely to roll over in a turn. When the top deck is loaded and the lower deck is empty, most of the weight sits higher above the axles, raising the centre of gravity. As you corner, lateral forces push the vehicle to lean outward; with a high CG, the roll moment is larger and the outer wheels can lift more easily, risking a rollover. The stability provided by a low, broad load isn’t present here, so the main hazard is overturning during cornering. Braking or gear choices aren’t the primary issue in this loading scenario, so the risk isn’t about brakes’ effectiveness.