'Not considering' should read 'now considering', right? My random thoughts: 60" is not bad, but as somebody who seems to be prone to bumping his head into stuff, a contraption that you could lift to 72" or so is even better. That (a hinged crossover) is what I have built for my layout. Your room seems to be only used for the railroad (and laundry), so maybe a five foot duck-under is perfectly fine. I still bump once a day into the lower half of my hinged 56" to 72" cross-over; good thing it's just foam. Along the lines of what Todd wrote: do you need double the layout area? Again, from my perspective, I know I have to keep an eye on 'buildability', and getting to a working layout within a reasonable amount of time. Can you stage building your layout? How are you attaching the benchwork to the wall? If you can just 'click in' the upper level supports into vertical shelving rails after finishing and operating the lower level, staging might not be so bad. Alternatively to the two level plus cross-over plan, how about a three foot wide entrance without duck-under, and four foot diameter circular peninsulas on both sides? Dogbone mainline turns around on viaducts, yard is on lower level. Rounding the corners of the four foot wide turn-around sections gets around the reach problem, and reduces the number of pointy things to bump into. By the way, I completely redesigned my yard after seeing your switch to a single double-ended yard.