Eight years ago I completed an outdoor O / on the ground setup using Atlas Track. It held up very well, but there were lessons learned, assumptions made, etc. Some parts didn't quite do what I expected while other parts exceeded expectations. For example: the Atlas track is UV stabilized. Except for the drawbars on the switch tracks. Those rotted out. Very strange, indeed.
I didn't use their switch motors (solenoids). In no way would those work with dirt / bugs / grime getting in them. I did construct specialized circuitry that listened to the TMCC serial data and controls servos (R/C cars or planes). These are sealed and lasted wonderfully. The circuits I built 8 years ago were bulky but reliable. I came up with a new design based on the Arduino micro-controller and wrote all the software for TMCC command control as well as anti-derail using outer-rail dead sections that the train can provide connectivity. The micro-controllers will move the switches in the direction of an on-coming train without operator interaction. The whole thing is quite small / tidy and works perfectly. This greatly reduced the wiring complexity of my setup as one nano Arduino can control 6 switches and receive 8 block detections!
I just went through and updated the entire setup from physical track layout, ballasting, switch control, and even un-coupler controls (don't need SC-2s or Accessory Track Controllers with the Arduino--it does everything better and cheaper).
I am thinking about writing a short e-Book and/or maybe some articles on how all this works. It was a lot of development, and I don't really want to keep it to myself. At the same time, most people have no interest in going outside (but I do think the servo controlled switches are far less obtrusive than the large solenoids). They look way better as the servo can be placed 1 inch away or several feet away hiding the machinery behind the magic.
If there is interest here, I'll be happy to contribute. If not, well, no hard feelings: it was a fun project (and more yet to come--thinking of an outdoor roundhouse using an Arduino controlled stepper motor tied in to TMCC control)....
I love the resource here. Although I have posted very little, this place has been a great source of ideas and help.
Thanks
-Randy