[cwillu]

High beams definitely do not get 100 meters of usable distance in fog, and in fact will reduce the visibility further.

https://www.weather.gov/safety/fog-driving says:

“

    • Use fog lights if you have them.
    • Never use your high-beam lights. Using high beam lights causes
      glare, making it more difficult for you to see what’s ahead of
      you on the road.

”