To reduce speed while going downhill in an automatic vehicle, you can:

To reduce speed while going downhill in an automatic vehicle, utilizing both lightly pressing the brake pedal and shifting to low gear is an effective method.

When lightly pressing the brake pedal, you are applying gradual braking force which helps control your descent and prevents excessive speed that can lead to loss of control. This technique is especially useful in maintaining a safe speed without abrupt stops that could cause instability.

Shifting to low gear helps to utilize the engine's braking power, which can slow the vehicle down without solely relying on the brakes. This is particularly advantageous on longer downhill stretches, as it helps prevent overheating of the brake components by reducing the need for constant brake application.

Combining these two techniques enhances safety and control, making it the best choice for managing speed effectively while driving downhill.