43.—(1) TfL may, whenever in its opinion it is necessary to do so, close either or both of the tunnels, whether wholly or partially.
(2) Where TfL proposes to close either or both of the tunnels, it must except in an emergency—
(a)give not less than 7 days’ notice in such manner as TfL considers appropriate; and
(b)throughout the period of such closure display signs at convenient situations on the roads communicating with the tunnels giving warning of the closure.
(3) In this article “emergency” means any circumstance existing or imminent which TfL considers is likely to cause danger to—
(a)persons or property, including the tunnels or any person in or using the tunnels; or
(b)the environment.