Transportation infrastructure in Romania is the property of the state, and is administered by the Ministry of Transport and Infrastructure, Constructions and Tourism, except when operated as a concession, in which case the concessions are made by the Ministry of Administration and Interior. The country's most important waterway is the river Danube. The largest port is that of Constanța, which is the second largest port at the Black Sea. With over 13 million passengers Bucharest Airport is a major international airport and European transportation hub. Air travel is used for greater distances within Romania but faces competition from the state-owned CFR's rail network. Public transport is available in most areas. History Romania has a system of large, navigable rivers, such as the Danube, Olt and Mureș that cross the country. The first important human improvements were the Roman roads linking major settlements and providing quick passage for marching armies. Railway transport A fast-growing number of Romania's major cities have modern tram or light rail networks, including Bucharest, Timișoara, Cluj-Napoca and Oradea. Recently the tram has seen a very big revival with many experiments such as ground level power supply in Oradea. Roads and automotive transport According to the CIA Factbook, in 2012 Romania had a total road network of 84,185 km, out of which 49,873 km were paved and 34,312 km unpaved. Romania's National Institute of Statistics (INS) 2019 transport report stated that total road network is 86,391 km: 38,166 km (44.2%) modernized roads (92.8% with asphalt pavements of heavy/medium type and 7.8% with concrete), 21,365 km (24.7%) with light asphalt road clothing, 17,831 km (20.6%) cobblestone roads and 9,021 km (10.5%) dirt roads. Motorways Motorways are identified by A followed by a number. As of December 2022, Romania has 995 km of highway completed with more under planning or construction. In recent years, a master plan for the national motorway network has been developed and approved by the European Commission in July 2015. Currently the A1 motorway, part of the northern branch of the Pan European IV Corridor, is open on 456 km. Under construction are the segments Curtea de Argeș—Pitești (30 km). Margina—Holdea (13 km) and Boița—Curtea de Argeș (73 km) have yet to start construction. It has a total length of 576 km. The A2 motorway was the first motorway in Romania opened on all its segments, with a length of 205 km. It links Bucharest to