The effect of the order is to prohibit vehicles from making a U-turn whilst proceeding on either the northbound or southbound carriageway of the A466 trunk road.
Effaith y gorchymyn hwn yw gwahardd cerbydau rhag gwneud troad pedol wrth fynd ar naill ai cerbytffordd tua’r gogledd neu gerbytffordd tua’r de cefnffordd yr A466.