Fog is baaaaad. A couple years ago I was driving to Tampa before dawn, going the usual 75mph, with all the other cars and all of the sudden we were just in fog...it was the weirdest thing. I didn't know if I should slow down (and risk getting plowed into from behind) stay the same speed (and risk plowing into somebody who did slow down or just stop). I couldn't tell if any cars were next to me, so I couldn't pull over, and I doubt I could have found the shoulder without creaming a gaurd rail anyway. I gradually made my way down to about 25 mph and kept driving through it (hoping everybody else decided to do the same). It lasted about 5 miles, I guess and it was horrible. I'd rather drive in snow. I couldn't imagine having to do that on a daily basis.