What is the significance of maintaining a lower gear when driving downhill?

Maintaining a lower gear when driving downhill is significant because it utilizes the engine's braking capacity to help control the vehicle's speed. When the bus is in a lower gear, the engine provides resistance against the wheels, which slows the vehicle down without relying solely on the brakes. This is particularly important when driving a large vehicle such as a school bus, as it helps prevent the brakes from overheating and ensures more effective braking control.

By downshifting to a lower gear, the driver can manage the descent safely, maintaining better control over the vehicle's speed and reducing the risk of loss of control due to excessive speed. This practice is especially vital on steep inclines where the potential for increased speed can be substantial. In contrast, relying only on brakes can lead to brake fade, making it harder to slow down the bus effectively.