When should a driver be using their headlights?

Using headlights from sunset to sunrise and during poor visibility is crucial for ensuring safety on the road. This is because headlights enhance a driver's ability to see the road and their surroundings in low-light conditions, such as at night or during periods of inclement weather, including rain, fog, or snow.

When visibility is compromised, whether due to darkness or weather conditions, headlights help other road users, including pedestrians and other vehicles, to see the driver's vehicle. This is essential in reducing the risk of collisions. Moreover, many states have laws that require headlights to be turned on during specific conditions, such as when windshield wipers are in use or when visibility is reduced to a certain distance.

Driving during the day only using headlights, as suggested in one of the alternatives, limits safety enhancements when natural lighting is insufficient. Similar concerns arise with the choice of using headlights only in clear weather or just in heavy traffic, as these scenarios do not account for situations where visibility can suddenly change, necessitating the use of headlights at times that are not immediately obvious. Thus, the specified times for headlight use highlighted in the correct answer focus on maximizing safety for all road users in various conditions.