(7) The sign shown in diagram 828 shall be illuminated by a means of internal lighting only during such times as it is necessary that the sign shall be illuminated for the purpose of indicating the information shown in the diagram relating to that sign.
(8) The signs shown in diagrams 560 and 561 shall not be illuminated by the fitting of a means of internal or external lighting.
(9) Subject to the foregoing paragraphs of this Regulation and to Regulation 19 every sign shown
(a) in a diagram in Part I and Part II of Schedule 1 other than the signs shown in diagrams 515, 536, 539 to 542, 545, 548 to 552, 554, 557 to 559, 562, 564 to 569, 603 to 605, 615 and 633 to 644, and
(b) in diagrams 701 to 712, 718 to 723, 727 and 729 to 731,
when erected on a road within 50 yards of a street lamp lit by electricity shall be illuminated throughout the hours of darkness by a means of internal or external lighting unless the sign is placed only temporarily on the road for the purposes of a temporary statutory provision or by reason of the execution of works or any obstruction on a road or some emergency.
(10) Subject to the foregoing paragraphs of this Regulation and to the provisions of Regulation 19, any sign shown in a diagram in Schedule 1 may be illuminated by a means of internal or external lighting.
(11) Subject to the provisions of Regulation 19, where any sign shown in a diagram in Schedule 1is to be illuminated by a means of external lighting, that means shall be either fitted to the sign or to the structure on which it is mounted or otherwise specially provided.
16. Where a sign shown in any of the diagrams 521 , 606 , 609, 612 to 614, 616 and 809 is placed on a road in connection with a statutory prohibition, restriction or requirement relating to vehicular traffic which does not apply at all times, the sign shall be illuminated by a means of internal or external lighting only during such times that it is necessary for the purposes of that prohibition restriction or requirement that the sign shall be visible from a reasonable distance to drivers of approaching motor vehicles.
75.—(1) The sign shown in diagram 560 shall be illuminated by the use of red reflectors when the sign indicates the near side edge of the carriageway or an obstruction near that edge and by the use of white reflectors when that sign indicates the off side edge of the carriageway or an obstruction near that edge unless the said sign is illuminated by the use of reflecting material in accordance with the provisions of the next paragraph of this Regulation.
(2) The said sign may and the sign shown in diagram 561 shall be illuminated by the use of red reflecting material extending over the whole surface when the sign indicates the near side edge of the carriageway or an obstruction near that edge and by the use of white reflecting material extending as aforesaid when that sign indicates the off side edge of the carriageway or an obstruction near that edge.
18.—(1) Nothing in this Regulation shall apply to the signs shown in diagrams 536, 560 and 561 , or to any sign shown in any other diagram in Schedule 1 which is at any time illuminated by lighting in accordance with the provisions of Regulation 15 or 16.
