Which situation requires the use of headlights according to traffic regulations?

The situation that necessitates the use of headlights according to traffic regulations is during rain or fog. This is because visibility is significantly reduced in these weather conditions, posing a risk to both the driver and other road users. Headlights help improve visibility not only for the person driving but also make the vehicle more visible to others on the road, which is crucial for safety.

When it rains or during foggy conditions, utilizing headlights can help illuminate the road ahead and provide a better view of obstacles or other vehicles. Additionally, other drivers can see the vehicle from a distance, which is especially important in low-visibility situations. Consequently, many regions have specific regulations stating that headlights must be used during adverse weather conditions to enhance safety for all.

In contrast, headlights are not exclusively required to be on during nighttime or merely in heavy traffic, unless visibility is compromised. These considerations are primarily focused on ensuring that drivers can navigate safely in conjunction with the visual capabilities of their vehicles in varying situations.