The seminar deepens the principles of track design and in this respect builds on the course superstructure – Basics course. After a brief description of the superstructure system, the focus is on the properties of superstructure components and their influence on load transfer In particular, the elasticity in the superstructure is addressed an the characteristics of the ballasted track and slab track systems are explained, as well as the possibilities of measurement technology in the track to record the system behavior. The course is rounded off with in-depth insights into track geometry quality and its influencing factors.