When driving in heavy fog, what actions should a CMV driver take?

DRIVING IN HEAVY FOG requires multiple simultaneous adjustments: REDUCE SPEED: This is the most important action. Your stopping distance must be within your sight distance — in fog, that may be 200 feet or less. Even at 25 mph, stopping a loaded truck takes 100+ feet. In severe fog, stop completely. HIGH BEAMS MAKE IT WORSE: High beams reflect back from water droplets in fog, creating a 'white wall' that reduces visibility compared to low beams. Always use LOW BEAMS or fog lights in fog. FOG LIGHTS: If equipped, front fog lights are mounted lower than headlights and angle downward — they illuminate the road below the fog bank. Rear fog lights make your vehicle more visible from behind in very thick fog. HAZARD LIGHTS: Appropriate if speed is significantly reduced from normal traffic speed. Some states have specific regulations about hazard light use while moving. PULLING OFF: If visibility drops to less than 100 feet, the safest action may be to pull completely off the road (not just onto the shoulder — parking on the shoulder in fog creates rear-end crash risk as other drivers may steer toward your lights); get well off the road, turn off lights (except hazards), and wait for conditions to improve. RADIO AND GPS: Consult radio for fog-related closures; some highways close in zero-visibility conditions. FOLLOWING DISTANCE: Double or triple minimum following distance in fog — stop lights in fog may not be visible until very close.