1941, decades of delays meant the Bucharest Metro was only opened in 1979. It now forms the backbone of Bucharest public transport network with an average of 800,000 passengers during the workweek. In total, the network is 71 km long and has 53 stations. Proposals to build metros have been put forward for Cluj-Napoca and Timișoara. Air transport The air traffic in Romania reached 20.28 million passengers in 2017 and 23.19 million passengers in 2019. The national carrier of Romania is TAROM, the largest Romanian airline is Blue Air while Wizz Air has the largest share of Romania's air transport market. Airports There are 20 airports in Romania (estimated as of 2006). Airports - with paved runways : 25 Runways over 3,047 m: 5 Runways from 2,438 to 3,047 m: 8 Runways from 1,524 to 2,437 m: 12 Airports - with unpaved runways : 36 Runways from 1,524 to 2,437 m: 2 Runways from 914 to 1,523 m: 11 Runways under 914 m: 23 Heliports 1 (2006) see: List of airlines of Romania and List of airports in Romania Water transport Romanian companies operate over 700 ships of which 400 are registered in Romania. Romania's 110 shipping firms employ 12,500 personnel at sea and 15,500 on shore. Each year, 105 million tonnes of goods and 1 million passengers are transported by sea. Marine transport is responsible for 52% of Romania's imports and exports. Ports With terminals: Port of Constanța (the largest port and shipyard in the Black Sea and one of the busiest ports in Europe) Port of Galați (on the Danube) Brăila (on the Danube) Tulcea (on the Danube) Other Black Sea ports: Mangalia Sulina Năvodari Other ports on the Danube: Giurgiu Drobeta-Turnu Severin Oltenița Ports on the Danube-Black Sea Canal: Cernavodă Poarta Albă Constanța Sud Agigea Waterways As of 2006, there are 1,731 km of navigable waterways of which: 1,075 km on Danube River 524 km on secondary branches 132 km on canals In 2004, according to europaworld.com, 19 million passenger-km and 4 billion ton-km were carried through these waterways. Merchant fleet The merchant marine has seen a dramatic drop in capacity during the first decade of the 21st century: from 142 ships ( or over) totaling / 1999 to 19 ships ( or over) / in 2007. These include: 13 cargo ships, 1 passenger ship, 2 passenger/cargo ships, 2 petroleum tankers, 1 roll-on/roll-off. 50 other ships are