.....A............
.....A............
.....A............
.....A............
BBBBBBBBXXXX
....................
CCCCCCCYYYY
Trying to make a easy chart... this is how it is now... with three lines (A,B and C) and two platforms (X and Y).
I now have a signal on A and B to make one of the trains wait if both want to enter plantform X.
What I want is choosesignals, making A,B and C all able to use either X or Y