Why should you avoid driving directly behind a truck or bus?

• It helps you see road signs better.
• It gives you a better view of the road and allows more room for an emergency.
  Explanation:

  "Do NOT drive directly behind a truck or bus. Keep a reasonable distance between your vehicle and the large vehicle ahead. This gives you a better view of the road to anticipate problems, and you will give yourself room for an emergency “out.""
• Trucks and buses stop more quickly than cars.
• It improves your gas mileage.