What is a key safety practice when driving down a long hill?

Using lower gears to maintain control and avoid brake overheating is essential when driving down a long hill. This practice leverages the engine's braking power, allowing the vehicle to decelerate smoothly without solely relying on the brake system. Long descents can lead to brake overheating, which compromises braking efficiency and increases the risk of brake failure. By shifting to a lower gear, drivers can help control their speed more effectively while minimizing wear on the brakes. This method enhances safety, helps maintain vehicle control, and ensures that stopping distances remain manageable, especially in the event of an unexpected situation.

The other practices suggested are not ideal for safe driving down a long hill. Accelerating to maintain speed can lead to loss of control and increase the risk of accidents. Constantly checking the rearview mirror is important for overall awareness, but it doesn't directly contribute to maintaining control during a descent. Lastly, using cruise control is not advisable on downhill slopes because it can lead to unintended acceleration and diminish the driver's control over the vehicle, particularly in changing road and traffic conditions.