When are headlights required to be on in most states?

Headlights are typically required to be on from sunset to sunrise and during inclement weather because these conditions significantly affect visibility. During nighttime, darkness makes it difficult for drivers to see the road and other vehicles, so using headlights is essential for safety. In addition, inclement weather such as rain, fog, snow, or heavy overcast conditions can reduce visibility even during daylight hours. By making it mandatory to use headlights in these situations, states aim to enhance safety for all road users by ensuring that vehicles are visible to others, allowing for safer driving conditions.

The requirement to turn on headlights during these specific times aligns with traffic safety regulations designed to reduce accidents caused by poor visibility. It helps to establish a clear standard that drivers can follow consistently, ultimately contributing to safer roadways.