When should headlights be turned on?

Headlights should be turned on when visibility is less than 500 feet to ensure that you can see well enough to navigate safely and be seen by others on the road. This guideline helps to improve safety during adverse weather conditions like rain, fog, or snow, where distances can be significantly reduced. Visibility being less than 500 feet indicates a significant reduction in how far you can see ahead of you, making it crucial to have your headlights on.

Using headlights in low-visibility conditions helps illuminate the road ahead and signals your presence to other drivers and pedestrians, thereby reducing the risk of accidents. While some might think 100 feet, 1,000 feet, or even 3,500 feet would be adequate benchmarks for using headlights, they do not provide the same level of safety and visibility assurance that the 500-foot rule does under typical driving conditions.