Dartford-Thurrock Crossing Act 1988

8The Secretary of State shall at all reasonable times allow and provide reasonable facilities for any authorised representative of the Port Authority—

(a)to inspect and survey the bridge and any works carried out on land adjoining the river in the course of operations for the construction, maintenance or improvement of the bridge affecting the river; and

(b)to inspect any works carried out in the river in the course of operations for the maintenance or improvement of the tunnels.