Paragraph 19 Particulars of the Barriers and Other Protective Equipment when the Road is Open to the Public.

Three electric lamps, each of not less than 5 watts nominal rating and with lenses of not less than 50mm diameter, shall be fitted to each barrier, one within 150mm of its tip, one near the edge of the carriageway, and one near the centre point between the other two. When illuminated the lamps shall show a red light in each direction along the carriageway.