I have been in one white-out here, in which I could not figure out what to do - luckily I was NOT on a highway, and it soon passed, but I literally could see nothing outside my cr except white everywhere, and it all looked the same. It was very dis-orientating. I imagine thick fog would be similar. BTW, these things (fog) happen in other parts of the country too. One thing that MIGHT help is for everyone to slow down, but not too suddenly (or no one vehicle should slow down too suddenly, unless all do).
I’ve only experienced whiteout conditions once in my life while driving, it is similar. I was on whatever interstate goes north from Minneapolis to St. Cloud, wind kicked up and boom, couldn’t see a blessed thing other than the tail lights of the car directly in front of me. Followed them off the edge of the pavement and nearly got the rental stuck.