Engineering work is taking place at Cardiff Queen Street, closing one of the platforms and some of the lines in the area from Saturday to Friday.
A reduced service will run between Cardiff Queen Street and Caerphilly.
On Saturday and from Monday to Friday, trains between Merthyr Tydfil and Aberdare via Cardiff Queen Street will not run via Cathays.
For travel to / from Llandaf / Cathays, you can use your ticket at no extra cost on Cardiff Bus services.
You can plan your journey using the National Rail Journey Planner.
You can plan your journey on buses by using the Traveline website.