This HO scale model railroad and is the first layout I've ever done. It uses the latest technology, Digital Command Control (DCC) that uses microprocessors within the locomotive housing to decode information sent up through the rails by the master computer.
Theoretically up to 128 individual locomotives could be placed on this layout, each separately controlled for speed, direction, lights and sounds like horn, bell, brakes. (Other sounds like air compressors, fans, coupler noises, and blowers are also available.)
A small portion of my layout Click for larger picture
My system can be controlled with a manual handheld device called a "cab" or "throttle" but also has all the electronics to allow me to control it by computer. The computer runs software that allows me to control every aspect of the layout, including dynamically displaying on a big monitor where my trains are. The layout has 11 turnouts (switches) that allow me to move the trains anywhere I want them to go. It also has the equivalent rail signal lights which are controlled by computer.
Automation and Lighting
A dozen videos of my layout, displaying lights and automation