If you must travel in fog or smoke, you should:

• Avoid crossing traffic unless absolutely necessary
• Keep radio off or turned down low and do not use cell phone
• Use wipers and defroster as needed for maximum vision
• All of the above
  Explanation:

  "If you must travel in fog or smoke you should: 1. Avoid crossing traffic unless absolutely necessary. 2. Listen for traffic (keep radio off or turned down low and do NOT use cell phone while driving in fog). 3. Use wipers and defroster as needed for maximum vision.Have good operating windshield wipers so that they do an effective job."