(1)The roads authority shall not, in the exercise of functions conferred by those provisions of this act which relate to cattle-grids, carry out any work in—
(a)so much of a road as passes over, or is comprised within the immediate approaches to, a bridge which is repairable by a person other than the authority;
(b)so much of a road passing under such a bridge as is within three metres of any part of the bridge or of the foundations thereof; or
(c)so much of a road passing above a tunnel provided for the purpose of a railway undertaking as is within three metres of any part of the tunnel,
except with the consent of the person liable to repair the bridge or the person carrying on the railway undertaking as the case may be.
(2)Where the consent mentioned in subsection (1) above is withheld, then—
(a)if the roads authority is the Secretary of State; or
(b)if the roads authority is a local roads authority and they refer the matter to the Secretary of State,
he may, after affording the person whose consent is required an opportunity of being heard by a person appointed by the Secretary of State for the purpose, and after considering the report of any such hearing, direct that the work be carried out notwithstanding that the consent has been withheld but subject to compliance with any conditions which the Secretary of State may impose.