When visibility conditions are impaired:
- Stay close to the vehicle in front, to be assisted by its lights.
- Keep to the right of the road and drive faster until visibility conditions improve.
- Correct answer: Drive slower and maintain a wider gap from the vehicle in front.
- Maintain normal speed, but remain constantly alert in case an emergency brake is required.
Why this is the answer
The correct answer in the official bank: Drive slower and maintain a wider gap from the vehicle in front.
In fog, heavy rain or dust you see hazards later, so there is less time to react and brake. Speed should match the distance you can actually see ahead, and the gap to the vehicle in front should be wider than usual. Staying close to follow its lights is dangerous, because if it brakes suddenly there is no room to stop.