Transportation 'Trains and Railways' No.09: Railroad Switch operation

After placing 3 rails next to a Railroad Switch to determine which is the straight line and which is the turnout direction, redstone power is needed to switch the Railroad Switch.

The player can place any power component or redstone dust (Button, Lever, Redstone Dust, ...) next to the Railroad Switch's only non-rail side and next to the turnout rail which is always a curved rail.
The text-based symbol for the 'redstone component' used below is:   [R]

      [H][H]
   [R][\][S][R]
         [H]

However, the switching needs to be double-sided rather than single-sided.
Single-sided (with just one redstone component) would be: no redstone power = straight, redstone power = switched
But the Railroad Switch has two sides which can receive a signal.

Double-sided switching is:
- Redstone power = change to or stay at that side
- No redstone power = no change

If the Railroad Switch receives a signal on the turnout rail, then the Railroad Switch switches to the turnout position (left or right) or stays there if already switched.
If the Railroad Switch receives a signal on the non-rail side, then the Railroad Switch switches to straight or stays there if already straight.
If the Railroad Switch receives a signal on both sides at the same time, then nothing will be changed.

The reason for using the double-sided switching method is that a double-sided Railroad Switch is much easier to 'remote-control' from a running train than a single-sided one.