Ключевые слова: alert, american, automobile, back, background, bad, black, board, caution, concept, course, danger, direction, driver, english, go, go back, illustration, information, isolated, message, metal, object, outdoor, post, road, roadsign, security, sign, signaling, signalized, states, stop, symbol, traffic, transport, transportation, travel, united, united states, united states of america, usa, warning, way, white, wrong, wrong way, wrong way sign,