If you can't see whats in front of you, pull over.
That's not exactly true in my opinion. In fact, from the article I read about the accident, the first people who pulled over could very well be the cause of the pile ups to start. I'm not saying that they had a choice, I don't know how bad it was...I wasn't there. But once you pull over or stop, it's not if your gonna get hit, but when.
I hit a dense fog just north of Louisville on I-65 in IN a few years back, the worst I've ever seen. You could barely see the white line well enough to stay in the road. Of course, I was worried about getting rear-ended, but I knew that if I stopped, I would definitely get hit. I slowed waaay down, turned on my flashers and eased up the road. I think I passed one off ramp simply because I couldn't see it until I was already past it. I found the next one and got off the road. I'm not sure that there is a good option if you find yourself in this situation, but I have never stopped and probably never will...until I can get completely off the interstate. It's just not a good place for parked vehicles.
Obviously, stopping ahead of time is the best answer, but you don't know your going into something like that at night..until your there.
