The railway network consists of around 500 km of track, with the two twin-line 'backbones' Venice-Trieste and Trieste-Udine-Tarvisio-Austria. The motorway and railway networks are linked to the ports of Trieste, Monfalcone and Porto Nogaro, the three most northerly ports of the Mediterranean. Trieste, in particular, has a free port for goods since 1719. It is the Italian port with the greatest capacity for covered storage, with a surface area of more than 2 million square meters and 70 km of rail tracks. Intermodality is guaranteed by the Cervignano terminal, in operation since 1988, to serve the increasing commercial traffic between Italy and Eastern European countries.