1. Tolls may not be levied in respect of—
(a)a vehicle whose details have been recorded on the exemptions register in accordance with Part 2 of this Schedule and, in the case of those listed in paragraphs 2(a) to (d), being used in the execution of duty; or
(b)a vehicle being used in connection with—
(i)the collection of tolls or charges; or
(ii)the maintenance, improvement or renewal of, or other dealing with, the Silver Jubilee Bridge or the new crossing or any structure, works or apparatus in, on, under or over any part of the new crossing or Silver Jubilee Bridge; or
(c)a vehicle which, having broken down on the Silver Jubilee Bridge or the new crossing while travelling in one direction, is travelling in the opposite direction otherwise than under its own power; or
(d)a military vehicle, that is, a vehicle used for army, naval or air force purposes, while being driven by persons for the time being subject to the orders of a member of the armed forces of the Crown.