Ключевые слова: area, attention, background, barrier, black, building, caution, chain, city, construct, construction, cross, danger, day, demolition, development, engineering, fence, forbidden, gate, industrial, industry, information, line, metal, new, nobody, orange, post, recondition, restricted, risk, road, safe, safety, scaffolding, security, sign, signboard, signpost, site, sky, symbol, technical, under, urban, warning, work, yellow, zone,