What is the safest driving procedure when encountering dense fog, heavy smoke, or severe dust storms on the road?

1. Slow down, switch on dipped low-beam headlights, increase following distance, and follow road edge markings
2. Turn on high-beam headlights to penetrate the fog further
3. Accelerate to pass through the dense fog cloud quickly
4. Drive along the centre of the road using your horn every 5 seconds