Ключевые слова: background, blue, bridge, clear, control, danger, direction, freight, high, industry, iron, journey, lamp, light, line, metal, nobody, old, outdoor, picture, pole, power, rail, railroad, railway, red, road, safety, sign, signal, sky, station, steel, stop, striped, structure, symbol, track, traffic, train, transit, transport, transportation, travel, view, water, way, white, wire,