During what condition must drivers use their headlights during the day?

Drivers are required to use their headlights during the day whenever visibility is reduced. This includes conditions such as fog, rain, snow, or any time when the natural light is insufficient to clearly see the road and surrounding area. The intent behind this requirement is to ensure that vehicles are more visible to others, promoting safety for all road users.

In contrast to this, using headlights only in bad weather or during daylight savings time is not a comprehensive rule; these do not encompass all scenarios that reduce visibility. Additionally, while some might think that headlights should always be used regardless of conditions, this could lead to unnecessary misuse of headlights when they are not needed, which can create confusion or glare for other drivers. Therefore, the focus on reduced visibility as the trigger for using headlights is key for maintaining safety on the road.