Mae'r gwaith wedi dechrau i drawsnewid rhwydwaith rheilffordd Cledrau'r Cymoedd fel rhan o gam 2 rhaglen Metro De Cymru, fydd yn cynnig gwasanaeth cyflymach a mwy rheolaidd i orsafoedd blaenau'r cymoedd a chysylltiad uniongyrchol â Bae Caerdydd.
Work is underway to transform the current Core Valley Lines rail network as part of the South Wales Metro Phase 2 programme, which will provide a faster and more frequent service for the heads of the valleys stations and a direct connection to Cardiff Bay.