The NS Public Highways Act contains many references applicable here, including:

• 11 (1) Except in so far as they have been closed according to law,
  (a) all allowances for highways made by surveyors for the Crown;
  (b) all highways laid out or established under the authority of any statute;
  (c) all roads on which public money has been expended for opening, or on which statute labour has been performed prior to the twenty-first day of March, 1953;
  (f) every road now open and used as a public road or highway; and
  (g) all alterations and deviations of, and all bridges on or along any road or highway,
  shall be deemed to be common and public highway until the contrary is shown.

• (2) Every common and public highway, together with the land within the highways boundaries, is vested in Her Majesty in right of the Province.

Even digging into a highway requires a permit:

47 (1) No person shall break up the soil of a highway without first making application in writing to a person employed in the public service of the Province in the Department of Transportation and Communications designated by the Minister, specifying the purpose for which it is required to so break up the soil, and obtaining his permission therefor in writing.

Perhaps most importantly

17 Possession, occupation, use or obstruction of a highway or any part thereof by any person for any time whatever, whether before, on or after the twenty-first day of March, 1953, shall not be deemed to have given or to give to any person any estate, right, title or interest therein, or thereto, or in respect thereof, but the highway or part thereof shall, notwithstanding such possession, occupation, use or obstruction be and remain a common and public highway