The new highways which the Secretary of State proposes to construct—
(a) along the route firstly described in the Schedule to this Order (the highway along this route being in the Order referred to as “the main new trunk road”); and
(b) along the routes secondly described in the Schedule to this Order which connect the main new trunk road with other highways at the places stated in that Schedule (the highways along these routes being in this Order referred to as “the slip roads”),
shall become trunk roads from the date when this Order comes into force.