In extremely foggy conditions, if you are driving at 45 mph in a 55 mph zone, you could be cited for:

• Driving too fast
  Explanation:

  "In dense fog or adverse weather conditions, it may be necessary to reduce speed significantly below the posted limit to ensure safety. Driving too close to the speed limit under such conditions can be deemed hazardous and may lead to a citation."
• Driving within the safe speed range
• Obeying the speed limit appropriately
• Driving too slow