“Mae'r terfynau cyflymder amgylcheddol o 50mya yn chwarae rhan bwysig wrth fynd i'r afael â llygredd ar rai o ffyrdd mwyaf llygredig Cymru, gan helpu Cymru a'i chymunedau i adeiladu dyfodol glanach, iachach a mwy diogel.
“The environmental 50mph speed limits are playing an important part in tackling pollution on some of Wales’ most polluted roads, helping Wales and its communities build a cleaner, safer and healthier future.