First, I’m a big fan; no surprise. Here’s why: with a small investment in benchwork, track and a control system you can have a layout, not just track on the carpet, up and running in a couple of days; and most of that is giving the glue time to dry. The benchwork itself is really simple, two straight modules and four corner modules which can be assembled in minutes (except for the drying time the glue needs) from kits. Screw down some Kato Unitrack with a terminal section; snap the modules together, and you have a double track oval layout. Connect a DC power pack and your layout is in operation. You can add structures and scenery later (most of us do anyway) to complete your layout.
A big reason I’m a fan is the benchwork is so simple. A six-foot by 30 inch folding table and six module kits and your benchwork is complete. With simple carpentry skills, some lumber and plywood you can build your own modules for less than the kits cost, but the kits give you exact dimensions in millimeters (a requirement when using Kato Unitrack), perfect alignment, pre-drilled holes for screwing down track, adjusting feet, and extremely simple assembly with ordinary carpenter’s glue. Kits from some manufacturers are press fit tab and slot construction so you don’t even need clamps. The track is what connects the modules and keeps them aligned. Two kit manufacturers with whom I have experience are Masterpiece Modules and CMR Products.
Two more reasons are: scale, and track. T-Trak modules use N scale track but larger radius curved track than the usual 9 to 9 ¾ inch radii found in a train set, so trains already look a little less toy-like. The standard track for T-Trak is N scale Kato Unitrack. It is a type of snap together sectional track; but this is nothing like the sectional track of days gone by. It has fairly realistic looking molded plastic roadbed, and it relies on a heavy plastic snap fit connection; not the rail and joiners themselves. It’s a solid enough connection that room sized and convention-sized T-Trak layouts rely on nothing more than the track itself to keep the modules together.
Another reason is simple wiring. Following the T-Trak wiring standard prevents most short circuits and permits easy expansion of the layout. It also permits tremendous variety in the way the modules are connected because most of the wiring faults that appear in double track railroads are automatically prevented. A good rule of thumb is to provide feeder wires on each straight module and connect the feeders at least every six feet to prevent voltage drops over long stretches of track. The main challenges to watch for are situations where trains cross from one track to the other, and arrangements where reverse loops send a train down the same track it just came from. As your wiring skills grow it’s still easy to adapt the T-Trak wiring to permit occupancy detection and signaling. And moving from DC to Digital Command Control (DCC) is as easy as just connecting the bus wires to the new control system.
The downside of building an entire layout in T-Trak modules is the uniformity, the lack of uniqueness that standardization enforces. At the risk of impacting reliability, a creative track planner can insert flex track and other non-Unitrack components between the ends of the modules to provide additional track and scenic possibilities. However, given the many examples of unique modules using standard components (T-Trak Wiki, Facebook, and T-Trak Standards) it is possible to create unique layouts and even to duplicate, schematically, many prototype track arrangements in T-Trak. For me, sacrificing scenic realism is ok if I can have the same schematic and operational options I would have with a custom layout.