When should high beams be used during nighttime driving?

High beams should be used on open roads to maximize visibility in situations where there is little to no oncoming traffic. They allow a driver to see further down the road, which is particularly important when driving in rural areas or on unlit highways where streetlights may be absent. However, it is crucial to dim high beams when approaching other vehicles or when being followed by another vehicle to avoid blinding other drivers. This practice promotes safety by ensuring that all drivers have adequate visibility without compromising each other's ability to see the road.

Using high beams in foggy conditions, as mentioned in one of the other choices, may not be effective since the light can reflect off the fog, creating a glare that reduces visibility. Similarly, it's not advisable to use high beams constantly or in all traffic situations since this can disturb other drivers. Therefore, the proper use of high beams is to utilize them when appropriate while being mindful of surrounding traffic conditions.