The lengths of existing highway —
(a) along the route described in Schedule 1 to this Order (the highway along this route being in this Order referred to as “the main trunk road”); and
(b) along the routes described in Schedule 2 to this Order which connect that part of the main trunk road with other highways at the places stated in Schedule 2 to this Order (the highways along these routes being in this Order referred to as “the slip roads”) and shown by black vertical stripes on the deposited plan shall become trunk roads as from the date when this Order comes into force.