The idea of the Traffic Screensaver is simple - little vehicle pictures are moving on the screen. The Traffic Screensaver is "programmable" - a configuration file, the "timetable file" defines the trains, the movements, the animations.
You can build trains from induvidual coaches, waggons and locomotives, determine the movements (simple run through, stop, stop and backwards, change loco, add coaches etc.), use animations (pantograph up and down, open and close doors etc.). The syntax allows random selections, repetitions of train parts. You can put pictures over other pictures (to change logos, to put load on freight waggons), to change the color of the pictures, to mirror pictures (but let some parts - texts - unmirrored) "on the fly" - so achieve greater variation from the same picture set. It makes use of transparent pictures, you can create background and foreground images using single pictures or combining many pictures together.
Fantastic