Mae dogfen yn amlinellu’r cyfrifiadau wedi cael ei chyhoeddi heddiw. Mae adroddiad arall sy’n amlinellu sut y byddai’r prif linellau yn y Gogledd a’r De yn elwa ar fuddsoddiadau (fel rhan o’r systemau Metro) wedi cael ei gyhoeddi hefyd.
A document setting out the calculations has been published today. Another report which outlines how investment would benefit for north and south Wales mainlines (as part of Metro systems) has also been published.