Since 1856, a series of tunnels have been constructed to conduct "the Bologna-Florence rail line", which is neither a single line nor a single tunnel. The Porrettana Line went into service in 1864, the Direttissima in 1934 and the High Speed in 1996. A few dozen tunnels support the three of them, the longest on the High-Speed Line being the Voglia Tunnel at . The longest is on the Direttissima, the Great Apennine Tunnel, which at is the longest entirely within Italy, although the Simplon Tunnel, which connects Italy and Switzerland, is longer. Automobile traffic is carried by the Autostrada del Sole, Route A1, which goes through numerous shorter tunnels, bypassing an old road, originally Roman, through Futa Pass. In December 2015, a new Route A1 called Variante di Valico was opened after many years of construction consisting of major tunnels (the longest being the new 'Tunel Base') and new overpasses, shortening the traveling time between Florence and Bologna by road. The Foreste Casentinesi, Monte Falterona, Campigna National Park is in the southern part of the Tuscan–Romagnol Apennines. The southern limit of the Tuscan–Romagnol Apennines is the Bocca Serriola Pass in northern Umbria, which links Fano and Città di Castello.