Although it would be a plus operationally to have larger diameter curves dedicated to the larger (Standard gauge) trains, visually having the smaller (0 gauge) trains on the outside loop is better. I would suggest using our STD57 curves inside of a 0-72 loop, or our STD84 curves inside of a 0-96 loop. STD42 curves are traditional, but operationally not so great.
Kirk Lindvig, USA Track LLC