[A]  Auto button provided for route indicated
[D]  Max aspect Yellow unless next signal showing Double Yellow or Green
[M]  Main route which is approach released from Red, max Yellow.
[R]  Main route which is approach released from Red
[Y]  Main route which is approach released from Yellow
[1], [2], [3]  Preference order of alternative routes 
{ }  Intermediate signals which are pre-set for this route

