4. The lengths of the trunk road described in Schedule 2 to this Order, and numbered 1–4 therein, and shown by broad striped hatching on the deposited plan, shall cease to be trunk road and numbers 1 and 3 shall be classified as classified roads and numbers 2 and 4 will become unclassified roads as from the date on which the Secretary of State notifies Gwynedd Council that the new trunk road is open for through traffic.