PPS 17 Control of Outdoor Advertisements·Page 10·5
Prohibition on obscuring traffic signs and navigation aids
Advertisements must not obscure or hinder the interpretation of road traffic signs, railway signals, or navigation aids, and must not render hazardous the use of roads, railways, waterways, or aerodromes.
No advertisement may be displayed on or so as to obscure, or hinder the ready interpretation of, any road traffic sign, railway signal or aid to navigation by water or air, or so as otherwise to render hazardous the use of any road, railway, waterway (including coastal waters) or aerodrome (civil or military).
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/PPS 17 - Control of Outdoor Advertisements.pdf