Provided that the light signals for conveying to pedestrians such information as aforesaid and which are associated as parts or the same electrical circuit shall he all of them of the same size, colour and type, that is to say, as shown either in the said diagram 4001 or alternatively in the said diagram 4002.
(2) The height of the lower edge or the container enclosing the light signals from the surface or the carriageway in the immediate vicinity shall be not less than 2.1 nor more than 2.6 metres.
(3) The said signals shall be so designed that—
(a) the red figure shown in the said schedule (hereinafter refereed to as "the red signal") can be internally illuminated by a steady light;
(b) the green figure shown in the said schedule (hereinafter refereed to as "the green signal") can be internally illuminated by a steady light; and
(c) when one signal is illuminated the other signal is not illuminated.
(4) (a) The period during which in the interests or safety pedestrians should not cross the carriageway shall be shown by the red signal during such time as it is illuminated; and
(b) the period during which in the interests or safety pedestrians should cross the carriageway shall be shown by the green signal during such time as it is illuminated by the steady light.
(5) A traffic sign of the size, colour and type shown in diagram 4003 may be erected for use in conjunction with either the sign shown in diagram 4001 or that shown in diagram 4002 for the purpose or conveying to pedestrians the indication specified above that diagram.
36.—(1) In this Regulation the expression "traffic lane" means, in relation to a road, a part of the carriageway having as a boundary which separates it from another such part, a road marking of the type shown either in diagram 1004, 1005, 1007 of 1013.1
(2) Light signals placed above the carriageway and facing the direction of the on-coming vehicular traffic may be used for the control of that traffic proceeding along the trains lane over and in relation to which those signals have been so placed and, subject to the provisions of this Regulation, shall be of the size, colour and type shown in diagrams 5002 and 5004 if placed above the carriageway of a road which is a motorway or shown in diagrams 5001 and 5003 if placed above the carriageway of any other road.
(3) The height or this centre or each such signal from the surface of the carriageway in the immediate vicinity shall be not less than 5.5 metres nor more than 9 metres.
(4) The said signals shall be so designed that—
(a) the red cross shown in diagrams 5003 and 5004 (hereinafter referred to as "the red cross") can be internally illuminated in such manner as to show at steady red light,
(b) the white arrow shown in diagrams 5001 and 5002 (hereinafter referred to as "the white downward arrow") can be internally illuminated by a steady white light, and
