Yn ôl Dirprwy Weinidog yr Economi a Thrafnidiaeth, Lee Waters, mae modd achub bywydau ar draws Cymru drwy leihau terfynau cyflymder diofyn o 30mya i 20mya.
Lives can be saved across Wales by reducing default speed limits from 30mph to 20mph, says Deputy Minister for Economy and Transport Lee Waters.