What can occur if spring brakes engage due to low air pressure?

When spring brakes engage due to low air pressure, the vehicle will come to a sudden stop. Spring brakes are a safety feature designed to activate automatically when air pressure drops below a certain level. This is critical because it prevents a vehicle from continuing to roll when there is a loss of air pressure in the braking system.

When the spring brakes engage, the powerful springs in the brake mechanism are released, clamping down on the brake shoes or pads to bring the vehicle to a halt. This mechanism ensures that, even in the event of a complete air loss, the vehicle has a fail-safe method of stopping, which is crucial for the safety of the driver, other road users, and the integrity of the vehicle itself.

The other choices reflect misunderstandings about how spring brakes function or the implications of low air pressure. For instance, the vehicle does not roll over as a direct consequence of spring brakes engaging; rather, it stops. Similarly, while low air pressure would indeed impair braking function if spring brakes did not engage, they do function to halt the vehicle immediately when pressure is insufficient. Lastly, instead of increasing driving speed, the activation of spring brakes serves precisely to prevent any further movement.