You should use your horn:

• To avoid collisions (when necessary)
• To alert pedestrians or other drivers of a hazard
• To alert oncoming traffic on narrow mountain roads where you cannot see at least 200 feet ahead of your vehicle
• All of the above
  Explanation:

  "

  You must use your horn to:
  1. Avoid collisions (when necessary).
  2. Alert another driver of a hazard.
  3. Alert oncoming traffic on narrow mountain roads where you cannot see at least 200 feet ahead of your vehicle.

  "