law: 4. National highways to vest in the Union.-
  All national highways shall vest in the Union, and for the purposes of this Act "highways" include-
  (i) all lands appurtenant thereto, whether demarcated or not;
  (ii) all bridges, culverts, tunnels, causeways, carriageways and other structures constructed on or across such highways; and
  (iii) all fences, trees, posts and boundary, furlong and milestones of such highways or any land appurtenant to such highways.