I always turn off at the nearest exit and wait the fog out over a cup(s) of coffee. I'd rather lose time than my life.
Merely slowing down with emergency lights turned on doesn't do a lick of good when a fully-loaded semi bears down on your rear at 70 MPH!
Leni
Thats true. What a scary thought! But sometimes if I am near an overpass I usually stop under it and wait the storm out. Fog is a different story. You can't really wait for the fog to lift.