I posted a picture in the photos section. It's a plan for 24 by 36
foot layout in a room, going for the maximum radius possible.
The layout can function as 2 independent loops and also as a
single "twice around" layout. The minimum radius is 6.25 foot and the
outer loop is 7 foot.
Just for fun. If you are planning a layout, I'd be happy to make up a
few for you with RR-Track, it's fun.