Ключевые слова: abstract, attention, background, backgrounds, blue, caution, clear, color, communicate, communication, concept, contrast, control, cross, danger, design, directions, drive, hazard, highway, idea, information, line, lines, notice, rail, red, roadside, safety, scenic, shape, sign, signal, sky, stop, street, symbol, symbolic, traffic, trail, train, transport, transportation, travel, trip, warning, way, white,