Ключевые слова: 40, automobiles, car, caution, circle, concept, drive, forty, highway, information, kilometers per hour, law, limit, maximum, miles per hour, mph, number, number forty, red, restriction, road, road sign, roadsign, round, safety, sign, sky, slow, speed, speed zone, street, symbol, traffic, traffic sign, transport, transportation, travel, urban, warning, white,