Acquire more space and longer towns and runs with multiple decks. Tony Koester walks you through design, options, lighting and wiring considerations, the where and when sequence, as well as the all-important construction techniques.
A good overview of multi-deck model railroads, but I would have liked to see more substantive case studies of the problems modelers have encountered and how they were overcome. It got me thinking, and has caused me to reconsider some of the ideas I had about the design of the railroad I intend to build, so I think it was worthwhile, but the title implies - at least to me - more information about design process and construction steps than is actually in the book.