Ключевые слова: abstract, areas, backdrops, background, backgrounds, barrier, barriers, chaos, color, colorful, concept, construction, contractors, crowd control, danger, designs, engineering, equipment, fence, fences, grid, industrial, job, many, materials, metal, net, nets, netting, nonobjective, off, orange, outdoors, over, pattern, plastic, property, protect, protection, road, safe, safety, security, site, urban, vertical, warning, work, workplace, yard,