4.—(1) Unless otherwise directed by an authorised officer, all tolls leviable in respect of vehicles using the specified roads shall be paid at one of the toll-booths situated near the south end of the specified roads.
(2) Unless otherwise directed by an authorised officer, every vehicle using the specified roads shall—
(a)stop in such a position opposite a toll-booth as will enable the driver to pay any toll without leaving the vehicle, and
(b)remain at rest until a visual signal is displayed at the toll-booth that the toll has been paid, or until an authorised officer permits or directs the vehicle to be driven off.
(3) Where the said visual signal is so displayed but is extinguished or replaced by a red light before the vehicle has passed it, the driver shall not proceed, and shall comply with the provisions of sub-paragraph (b) of paragraph (2) of this regulation.