“Mae lle i wella bob amser wrth wella diogelwch ar y ffyrdd, ac mae gan bawb gyfrifoldeb dros wella diogelwch a chwarae eu rhan.  Mae terfyn cyflymder amrywiol yr M4 yn un elfen o’r dulliau amrywiol y mae Llywodraeth Cymru yn eu defnyddio i wella diogelwch ar y rhwydwaith priffyrdd a chefnffyrdd yn gyffredinol.
“There is always room for improvement in road safety and everyone has a responsibility for improving safety and playing their part.  The M4 variable speed limit is just one element of a multifaceted approach the Welsh Government takes to improving road safety on the motorway and trunk road network as a whole.