What does the red circle and slash on a white background sign mean?

• It indicates a permitted action.
• It provides information about nearby attractions.
• It indicates a prohibited action.
  Explanation:

  "A red circle with a slash on a white background is a prohibitory sign. It indicates that a specific action is not allowed. For example, a sign with a red circle and slash over a left-turn arrow means that left turns are prohibited."
• It gives directions to the nearest highway.