If you are taking part in the Cardiff Half Marathon, you might want to check out which routes have been impacted.
No trains running from Merthyr Tydfil, Aberdare or Treherbert to Radyr
From Saturday 28 September to Sunday 6 October, no trains will run from Merthyr Tydfil, Aberdare or Treherbert to Radyr for nine days.
Buses will replace trains between Treherbert, Merthyr Tydfil, Aberdare and Radyr, with all train services to Cardiff Central starting and terminating at Radyr.
For those travelling to the Cardiff Half Marathon on Sunday 6 October, Transport for Wales will be running additional bus services.
These will be from Merthyr, Aberdare and Treherbert, alongside an additional early morning rail service from Radyr which gets into Cardiff before 9am.
The closure is to allow teams to carry out 30 pieces of engineering work, which will allow four trains an hour to operate from the head of each valley.
It includes track and signaling upgrades at Pontypridd station, the removal of the original Treforest station footbridge for donation to a heritage railway, and track-side cleaning.
Engineering works at Cardiff Queen Street Station
Engineering works will take place through Cardiff Queen Street station from Sunday 27 October to Sunday 03 November.
This is to carry out essential track and signaling upgrades in preparation for more trains to run through the station.
Several lines will be affected, with no rail services running on the Coryton, Rhymney or Penarth lines.
Transport for Wales advises passengers to check before they travel as there will be rail replacement buses in operation or ticket acceptance with bus operators.
The ticket office at Cardiff Queen Street station will remain open throughout the closure to allow passengers to purchase tickets and find information on services.
