Job For Fog Sign Holder

[Losty]

How can they see the sign if it's foggy? And do they really need to be told?

In my travels, as you're passing through the fog you see bright lit up signs advising you of the fog you're driving through. Then when the fog cleared there was a sign letting me know the fog was over. Thankful for fog advisory signs, else I'd have never been able to tell where the fog began and where it ended.