Over 100 pre-existing routes from previous versions (TS2014 and earlier) remained compatible with the 2015 engine. Update v49.4a Technical Highlights

The "incl. DLC" tag in this release indicates the inclusion of various expansion packs. While the exact list varies by specific repacks, major official DLC categories available during the 2015 era included:

A vast library of steam, diesel, and electric trains, including the BR Class 101.