The effect of the Order is to temporarily prohibit vehicles on lengths of the A487 trunk road at Caernarfon Flyover to undertake works on or near the road.
Effaith y Gorchymyn yw gwahardd cerbydau dros dro ar ddarn o gefnffordd yr A458 yn Llanfair Caereinion er mwyn gwneud gwaith ar y ffordd neu gerllaw iddi.