This deliverable describes important aspects of migration and explain possible migration paths and cases for upgrading ballasted tracks on rail freight corridors (RFCs) by slab track developed in C4R. Upgrading the track on a highly loaded rail freight corridor, where the use of slab track make sense, is a very challenging task for migration. The basis for the decision are criteria like • Capacity bottleneck due to track availability and high maintenance • Availability of alternative routes • Proofed slab track available for given boundaries or • Homogeneous and stable support conditions