“Making the change from 30mph to 20mph could result in 40% fewer collisions every year, with 6 to 10 lives saved and between 1200 to 2000 people avoiding injury.
"Gallai newid o 30mya i 20mya arwain at 40% yn llai o wrthdrawiadau bob blwyddyn, gyda 6 i 10 o fywydau'n cael eu hachub a rhwng 1200 a 2000 o bobl yn osgoi anaf.