Ключевые слова: blue, built in stone, contrast, danger, delay, do not pass, drive, driving, europe, forbidden, indication, isolated, mandatory, objective, objects, octagon, octagonal, portugal, precaution, red, road, safety, security, shadow, sign, sign shadow, sky, southern europe, stone blocks, stone wall, stop, stop sign, street, symbol, texture, to control, traffic, transit board, transport, universal, wall, warn, white,