What action should be taken when visibility is reduced to 500 feet?

When visibility is reduced to 500 feet, using your headlights is essential for ensuring your safety and the safety of others on the road. Headlights enhance your visibility by illuminating the roadway, making it easier to see ahead and spot any potential hazards. This action also makes your vehicle more visible to other drivers, reducing the risk of collisions.

Driving without headlights in low visibility conditions can lead to dangerous situations, as other drivers may not see you until it's too late. Increasing your speed is inappropriate and unsafe, as it can diminish your ability to react to obstacles or changes in road conditions. Pulling off the road might be a viable option in extreme visibility scenarios, but it is not practical or necessary when visibility is only reduced to 500 feet; using headlights is sufficient to navigate safely. Therefore, using your headlights is the correct response to maintain safety in such conditions.