The effect of the Order is to prohibit the making of right hand turns on the A465 trunk road west of Hirwaun Roundabout in Rhondda Cynon Taf which is considered necessary on road safety grounds.
Effaith y Gorchymyn yw gwahardd troi i'r dde ar gefnffordd yr A465 i'r gorllewin o Gylchfan Hirwaun yn Rhondda Cynon Taf ac ystyrir bod ei angen ar sail diogelwch ar y ffordd.