It is recognised that a speed limit of 20mph may not be appropriate for all restricted roads in Wales, however, and an ‘exceptions process’ has therefore been developed.
Fodd bynnag, cydnabyddir efallai nad yw terfyn cyflymder o 20mya yn briodol ar gyfer pob ffordd gyfyngedig yng Nghymru, ac felly mae ‘proses eithriadau’ wedi’i datblygu.