Ключевые слова: alertness, all way, at, attention, business, center, city, communication, concepts, control, danger, decisions, direction, halt, information, intersection, law, low, message, metal, no, object, octagon, post, red, risk, road, road sign, roadside, safety, shape, shiny, sign, signal, single, speed, stop, stop sign, street, symbol, text, traffic, transportation, urban, view, waiting, warning, word,