When driving in fog, which of the following should you do?

In fog, use low beam headlights and slow down. High beams reflect off the water droplets in fog and create a wall of glare that actually reduces your forward visibility. Low beams aim downward and cut under some of the reflection. If your truck is equipped with fog lights, use them — they are designed to spread light low and wide where it is needed. Slowing down is the most important adjustment because stopping distance in fog must fit within the limited visibility ahead. Following closer to the vehicle ahead is dangerous because if they brake hard, you have no room to react. Hazard flashers while moving are illegal in some states and confusing in any. If visibility drops below safe limits, pull off the highway and wait it out.