It shows weighted mean speeds on a sample of main restricted roads in Wales reduced by an average of 4mph over the three months after the default speed limit was introduced.
Mae’n dangos bod cyflymderau cymedrig pwysol ar sampl o brif ffyrdd cyfyngedig yng Nghymru wedi gostwng 4mya ar gyfartaledd dros y tri mis ers cyflwyno’r terfyn cyflymder diofyn.