What should vehicle drivers do when the red light begins to flash on this sign and a bell starts to ring?

• Get ready to go when the lights begin to flash and the bells ring because a train is approaching.
• Stop when the lights begin to flash and the bells ring because a train is approaching.
  Explanation:

  "Stop when the lights begin to flash and the bells ring because a train is approaching."
• Start when the lights begin to flash and the bells ring because a train is approaching.
• It depends on what the speed of the train is.