Corridors, baselines, regions, assemblies, subassemblies, corridor surfaces
Custom subassembly .NET design — CorridorState, SubassemblyGenerator, targets, SATemplate
Stock-subassembly pattern catalog — need→file index, worked DrawImplement recipes, point/link/shape code reference, mined from Autodesk's 120 VB stock subassemblies
Superelevation design, attainment, cross slope, pivot points, lane config
Block definitions, references, attributes, dynamic block properties, exploding
Dimensions — aligned, rotated, arc, radial, angular, ordinate, text overrides
Dynamic text fields — field codes, evaluation, embedding in MText/attributes
Points, vectors, matrices, curves, planes — transforms, intersections, recipes