Ключевые слова: alert, attention, barrier, blue, caution, clouds, cross, crossing, danger, day, direction, equipment, freight, hazard, infrastructure, landscape, light, lights, mountain, outdoor, outdoors, protection, rail, railroad, railroad crossing, railway, red, road, roadway, route, safety, sign, signal, sky, stop, sunny, system, track, traffic, train, transit, transportation, travel, view, warning, way, white,