Yn y cyfamser a chyn unrhyw newid mawr o’r fath, rwyf hefyd wedi cyhoeddi dogfen ‘Gofynion o ran gwella prif linellau rheilffordd’ sy’n tynnu sylw at y ffordd y gall buddsoddiad strategol ym mhrif reilffyrdd gogledd a de Cymru, fel rhan o systemau Metro, helpu i fynd i'r afael â rhai o’r problemau rwyf wedi sôn amdanynt heddiw.
In the meantime and in advance of any major change of this kind, I have also published a document ‘Mainline railway enhancement requirements’ highlighting the ways in which strategic investment in the north and south Wales mainlines, as part of Metro systems, can help to address some of the issues I have highlighted today.