Ключевые слова: 40, background, circle, communication, drive, forbidden, forty, highway, information, international, junction, kilometer, km, law, limit, limited, maximum, measurement, number, outdoor, pole, post, prevention, prohibition, prohibitory, protection, quadratic, red, regulation, regulations, road, route, rule, safety, sign, signal, slow, speed, speeding, street, symbol, system, traffic, transportation, travel, warning, white,