A "Route" is the building block upon which "Sessions" are built. A Route is comprised of "Layers" including terrain, ground textures, scenery objects, splines, tracks, trackside objects, environment settings, water, trains and rolling stock. Some of these items can also be part of a Session Layer.
Routes are created using the Help:Surveyor Tools by either starting from scratch or editing an existing Route. Routes can be as simple as a short loop of track or a fully prototypical route which accurately recreates your favorite section of real world track.