Refuge indicator lamps
57. A lamp in the form of an illuminated spherical globe for conveying the warning that drivers of vehicles are approaching a street refuge may be placed subject to the following conditions—
(a)the globe shall be white;
(b)the globe shall have a diameter of not less than 275 nor more than 335 millimetres; and
(c)the height of the centre of the globe above the surface of the carriageway in the immediate vicinity shall be not less than 3800 millimetres nor more than 5000 millimetres.