What do the warning devices and signs mean in a light rail transit crossing?

• These warnings mean stop and do not cross the tracks.
  Explanation:

  "LRT systems are powered by electricity, which makes them very quiet. These crossings use a variety of warning devices like regular traffic signal lights, signs, bells, and gates. These warnings all mean stop and do not cross the tracks."
• These warnings mean to start and cross the tracks.
• These warnings mean to tell the vehicles to speed up and cross the tracks.
• None of the above.