What does this sign mean?

• You are not allowed to smoke in this zone.
• You cannot idle your vehicle's engine for more than 3 minutes.
  Explanation:

  "This road sign informs drivers that they are not allowed to idle their vehicle's engine for more than 3 minutes. Idling refers to running the engine while the vehicle is stationary. This sign's purpose is to reduce air pollution and conserve fuel by limiting unnecessary engine running."
• Idling is permitted in the area.
• you cannot wait here for more than 3 minutes