Yes " there are more interesting and more realistic ways to add operating challenge than through artificial tricked out puzzles ". Sure, a 4% grade, a main line as default yard drill-track, turning a loco that is 2' longer than turntable bridge, double heading non-consisted steam (2 seperate engineers/2 throttles as real steam Ops had to be done ). Hmmm, what else ? Oh, if DCC , a head on collision ! A switchback in a yard is not an "artificial tricked out puzzle.". It's an actual 1:1 puzzle; not abundant, but never the less exists in railroading throughout the world ...Tracks are not installed first, then industries built next to them. Buildings (except for modern day industrial parks) are/were built, many times, years before a rail line was ever in the vicinity using truckers or dreys, horse and wagon, servicing them, to/ from distant rail line. Now we have companies, usually near rivers (no DWP yet), scattered with dirt roads all around. RR approaches owners/executives and offers to add a line in to them. Same for others. 5 out of 7 buy in. town grows. Problems crop up as to reaching each; a switch here, a diamond here, a wye switch there, sharpest curve there, 2 parallel .25 mile spurs there, etc., and at different times due to new or defunct buildings. 6th Company 3 yrs later changes its mind. All of this at times dictating the only possible track configuration, a switchback ... Hope you locate the special Model Railroader issue that " which I guess you didn't take time to read ", either.