What do you do if visibility is drastically reduced by fog?

When fog reduces visibility, you must drive more carefully because you can see less of what lies ahead. The rules require that you reduce your speed so that you can react in time to hazards that might appear suddenly. It's also important to increase your following distance, as stopping distances become longer in foggy conditions. Driving too close to the vehicle in front is dangerous, even if you think using its rear lights as an orientation point helps. It's much safer to slow down and leave more space, as you correctly selected. This way, you have enough time to stop if the car ahead brakes suddenly. Always prioritize safety by matching your speed and distance to the reduced visibility.