In which situation is using high beam headlights necessary?

Using high beam headlights is necessary on poorly lit roads with no oncoming traffic because they provide greater visibility by illuminating a larger area and further distance than low beam headlights. High beams allow drivers to see obstacles, pedestrians, and other potential hazards more clearly in dark areas where there is little to no ambient light. This enhances safety during night driving, especially on rural or isolated roads.

In contrast, in urban areas with streetlights, the use of high beams is not needed as the streetlights provide sufficient illumination for safe driving. During sunny daytime driving, high beams would be unnecessary and could cause glare to other drivers. Additionally, using high beams in heavy rain can create problems because the light reflects off the rain droplets, impairing visibility instead of improving it. Therefore, the correct answer emphasizes the importance of adapting headlight usage to the driving environment to ensure the safest conditions.