For better travel planning:
a selection of major construction sites of Deutsche Bahn for 2025 was published recently in German language:
https://www.bahn.de/service/fahrplaene/baustellen/baustellen_2025
Use DeepL for best translations from / to German.
One main focus with impact until 2026 will be the high-speed connection between Germany's two largest cities Berlin and Hamburg.
Previous thread about construction sites in 2024 - most willbe finished before holidays' traffic:
https://community.ricksteves.com/travel-forum/germany/deutsche-bahn-starts-first-two-around-frankfurt-of-14-major-construction-sites-in-germany-2024
Have good journeys!