Pea soup is one slang term for thick fog.
Misting, or condensation.
mystified.
It's an insult, another word for stupid.
"Corduroy" is a thick cloth with ridges.
Here's the answer given in Timberwoof's Motorcycle FAQ: Parts of California commonly get patchy thick fog. Interstate 5 and other highways commonly are the scenes of multiple-car pileups resulting...