roll, two, train, railroad tracks, ready, train station, railroad station, railroad trains, railway station, double, trouble, usa, route, tracks, engines, mighty, railroad train, 66, historic, yard, engine, needles, locomotives, california, motor, facility, united states, course, simple leaf, dual, path, station, railroad track, machine, acerate leaf, leaf, district, terminal, state, wheeled vehicle, vehicle, America, american state, sixty-six, track, United States of America, U.S., United States, difficulty, 2, plant part, needle, cognitive factor, north american country, public transport, historical, problem, locomotive, road