Driving In Heavy Fog

We visited an uncle in the province yesterday. He related his experience on the previous night when he was coming home from a relative’s house about 5 kilometers away. He was in the main road at around 9 pm when the fog appeared. It was so heavy, truly a visibility zero situation that he had to pull over. He said that it is foolish to drive in that situation especially in their place that is mountainous. What if he misses the road and falls on a ravine? That is a good lesson for us because in the past days, I had experienced driving in heavy rain that is also visibility zero. But I did not pull over because I used the lights of the car ahead of me as my navigational guide.