This system is used 4 RCXs to control 2 trains, 1 car and 1 level crossing.
RCX1 is used to control 3 switch points and response 3 light sensors.
RCX2 is used to control 3 segments track and response 2 light sensors.
RCX3 is used to control level crossing and response 2 light sensors.
RCX4 is used to control car.
The programming language is brickOS. Here is the whole layout. You can find
others image at http://www.brickshelf.com/cgi-bin/gallery.cgi?f=331237 .
The video on Youtube at http://www.youtube.com/watch?v=8XOOenaIdJ0 .