BC,
Seven year ago, I made a kids layout for them to use while I worked on the big layout. My kids were just entering elementary school and it gave them ownership of the layout. I did two loops with two level. The bottom level had switches, and operating track sections. It has tunnels and bridges to allow the top level to run over the bottom level. We picked a winter scene. Another forum member MISS C. did a similar plan with a city scene.
I not sure if I have the RR trax plan anymore. The layout was dismantled and moved into my larger layout after we did work on the basement. At that time my kids wanted to just use the big layout.