When driving on a highway at night, you should never use your high-beam headlights if you are:

Using high-beam headlights while driving at night can be extremely disruptive to other drivers. When you are following another vehicle, using high beams can create significant glare in their rearview mirror, impairing their ability to see clearly and safely navigate the road. It is important to maintain a safe and considerate environment for all drivers on the road, and lowering your beams when following another car is crucial for safety.

In contrast, slowing down for a turn, traveling on a road with no median, or going downhill may not pose the same level of risk associated with using high beams. It is more about ensuring that your actions as a driver do not compromise the visibility and safety of those around you, particularly when close to another vehicle. Thus, it is advisable to use low beams in these situations to promote safer driving conditions for everyone on the roadway.