[RegulatorCountry]

There has been a series of electronic speed limit signs on I-40 in the mountains of North Carolina for over 30 years. It’s activated by poor visibility, the lower the visibility the lower the speed limit. Fog is the problem on that stretch. I’ve driven through there when the speed limit was 5. We were hanging our heads out the windows looking for the lines on the road. Afraid to stop, for fear of getting rear ended.

[Rashputin]

I've been through there when it got that bad and everyone was driving with their hazard lights on as that's the only way you could tell where the car in front of or behind you was, from the glow in the fog the hazards made.

It cleared up in an hour but dang, it seemed like six hours to me.