As we take a design from the conceptual to detail stage, foremost in our mind should be the realization that what we draw WE must build.   What may take a few passes of pencil on paper to draw, may take quite a while to construct.   There should be a direct relationship between the amount of time (or hassle) it takes to build something and the utility or play value it provides.  If a complex feature is included in a design, then the expectation should be that it provide a larger than average payoff down the road.

It’s important, particularly for those building their first layout,  that construction proceed methodically to the point where trains can be run without constantly getting bogged down by assembly challenges at every turn.  It is also critical that once the track work is finished that the layout be reasonably comfortable to interact with.  In our early enthusiasm, Rube Goldberg design shortcuts may be tolerable but, over time, they can sap our enthusiasm to the point where we don’t even want to deal with the layout.  Listed below are five features that are commonly requested by my design customers.  There is nothing inherently good or bad about any of them as long as the layout owner has their eyes wide open as to what they are getting into.  I fear that frequently they do not.

Grades: Grades or slopes aren’t super difficult to build but they are certainly more involved than laying level track.  In particular, care must be taken in the vertical plane to ensure that the transitions into and out of the slopes are smooth.  You also have to construct risers to support the slope and take care to make sure you have clearance at any point one track passes over another.  Trains of any length at all can only handle so much slope.  A two-inch rise every eight feet (two percent roughly) is considered pretty stiff.  If you have a continuous run design what goes up must come down.  Since yards, sidings, and spurs must be flat, all of this rise and fall must be accomplished in areas between these features.  For a small to medium size layout that is a lot to make happen vertically in a short distance.  If you love watching a pusher on the back of a train, by all means incorporate the grades.  If you really, really love one track passing over another, design that in.  However, if you are somewhat ambivalent, keep your track level.

Double Deck Designs With a Helix:  I hear it all the time, “Oh I think I’ll just throw a helix in and double deck the layout”.  Well, you don’t just ‘throw a helix in’.   Helixes are complex to construct and contain an enormous amount of track.  That track will have to be cleaned.  If a car derails, somebody has to wiggle their hand between the helix coils to re-rail it.  Because of the very long mainline run length of a helix, the time waiting for a train to spiral from one deck to another can be unbearable.  With double deck layouts, NEITHER deck is at the ideal level.  Lighting below the top deck must be factored in as a cost and construction issue.   Double deck layouts are most suited for prototype operations enthusiasts where a long main line run is critical to their needs and they are willing to put up with the negatives.  In most cases they are not appropriate for a first layout attempt.

Signaling and Animation:  Grade crossing gates, lights, and crossing bell sounds require approach sensors, complex linkages, and fragile wiring.  Make sure the thrill of watching those red lights flash and the gates drop is worth the construction effort.  If so, go for it!  Fully operational signal systems are a hobby in and of themselves.  You don’t just plant the signal mast and flip a switch.  Blocking, occupancy detectors, and logic boards must be installed for the system to work.  Some forms of occupancy detection require special wheels on the rolling stock.  How thrilling is it for you to see that LED go from red to green?  Enough to double the amount of time you spend building the layout?

Tunnels:  Tunnels are popular. Before designing a lot of them in, long ones in particular, remember Murphy’s Law of Model Railroading.  It goes like this, if a train stalls or breaks down it will do so at the point on the layout that is most difficult to reach.  Do you want to be reaching three feet down a tunnel to grab that derailed car? To clean the track? In addition, many people find it unnerving to have a train out of sight for more than a few seconds.  Consider a series of short tunnels instead of one long one.  In some locations consider a cut instead of a tunnel.

Hidden staging:  For those enthusiasts that enjoy operations, a staging yard to represent the outside world is a must.  However, it’s all to easy to take the design easy out and just bury the staging tracks under the layout or behind a building.  In such haste, the same access issues mentioned with the tunnels raise their ugly head.  Every effort should be made to have your staging be open topped, even if it means cutting back a little on the actual layout itself.  Hidden staging should be an absolute last resort and reserved for those that are crystal clear as to the hornet’s nest they are getting into.

Again, there is nothing wrong with incorporating any of the above features provided they provide a value in your mind equal to the inconvenience of building or interacting with them.  Just know what you are getting into.