Any person authorised in writing in that behalf by the licensing authority under Schedule 3 to this Act for the area in which any track or the greater part of the superficial area thereof is situated, subject to the production on demand of his authority, and any constable, may at all reasonable times enter upon that track for the purpose of ascertaining whether the provisions of this Part of this Act are being complied with; and every person who obstructs any constable or other person in the exercise of his powers under this section shall be liable on summary conviction to a fine not exceeding F1level 1 on the standard scale.