This additional infrastructure was designed to facilitate the running of additional rail services on the Rhymney and Taff Vale corridors, between Caerphilly, Pontypridd and Cardiff.
Cynlluniwyd yr isadeiledd ychwanegol i hwyluso rhedeg gwasanaethau rheilffyrdd ychwanegol ar goridorau Rhymni a Chwm Taf, rhwng Caerffili, Pontypridd a Chaerdydd.