What protective measure should be taken during poor visibility conditions?

Using headlights during poor visibility conditions is essential for several reasons. First, headlights enhance your own visibility, allowing you to see the road and any hazards in front of you more clearly. Simultaneously, they increase your vehicle's visibility to other drivers, which is crucial in conditions such as rain, fog, or night-time driving when sightlines are reduced. This dual function helps prevent accidents by ensuring that both you and other road users can see each other.

While reducing speed is important in poor visibility, it is not a substitute for using headlights. Using the horn frequently might alert others, but it doesn't improve visibility and can lead to confusion. Following another vehicle closely is also counterproductive; it reduces the effective stopping distance and can create a dangerous situation if the lead vehicle slows or stops unexpectedly. Therefore, using headlights stands out as the most effective and necessary protective measure during such conditions.