(2) Subject to the provisions of the last and the next paragraph and of Regulation 19, every sign shown in a diagram in Schedule 1 shall be illuminated by the use of reflecting material in accordance with the provisions of paragraphs (5), (6) and (7) of this Regulation.
(3) The requirements of the last preceding paragraph shall not apply to the signs shown in diagrams 637 to 641, 643, 644, 739, 740, 742, 826, 833 to 836 and 841 to 843, and shall not apply to any signs shown in diagrams 636, 642, 734 to 736, 743 to 746, 801 to 808, 810, 812, 813, 815 to 820, 827, 829 to 832 and 840 if any such sign is so illuminated by street lighting throughout the hours of darkness as to be legible from a reasonable distance by drivers of approaching motor vehicles.
(4) Subject to the foregoing paragraphs of this Regulation and to Regulation 19, any sign shown in a diagram in Schedule 1 other than those shown in diagrams 637 to 641 may be illuminated by the use of reflecting material in accordance with the following provisions of this Regulation.
(5) Subject to paragraph (6) of this Regulation, where reflecting material is used on any sign shown in a diagram in Schedule 1 it shall be of the same colour as that of, and extend throughout, that part of the sign to which it is applied:
Provided that—
(a) no reflecting material shall be applied to any part of a sign coloured black,
(b) no reflecting material shall be applied to that part of any sign shown in Part III of Schedule 1 which is coloured green, and
(c) no reflecting material shall be applied to that part of the sign shown in diagram 738 or to that part of any sign shown in Part V of Schedule 1 which is coloured blue.
(6) Where in accordance with the last paragraph, different colours of reflecting material are used immediately adjacent to one another on the same sign, a gap of not more than ¾ of an inch in width nor less than ¼ of an inch in width may be left between the different colours of reflecting material.
(7) In the case of the signs shown in diagrams 515 and 569 white reflecting material shall be applied to the white chevrons.
19.—(1) Where a sign shown in a diagram in Schedule 1 (not being a sign consisting of a plate) is illuminated by a means of lighting in accordance with the provisions of Regulations 15 or 16 and a plate shown in a diagram in that Schedule is used in conjunction with that sign, the said plate shall, unless the means of lighting provided for the illumination of the sign adequately illuminates the plate, be illuminated during such times as the sign is illuminated by a means of lighting and that means of lighting shall accord with that one of the methods of lighting, namely, internal or external adopted for the illumination of the sign.
(2) Where a sign shown in a diagram in Schedule 1 (not being a sign consisting of a plate) is illuminated by the use of reflecting material in accordance with the provisions of Regulation 18 and a plate shown in a diagram in that Schedule other than those shown in diagrams 637 to 641 is used in conjunction with that sign, the said plate shall be illuminated by the use of reflecting material in accordance with the provisions of paragraph (5) of the said Regulation 18.
