disaster, in 2011 the government announced plans to end the use of nuclear energy in the following 2 or 3 decades. In November 2016, Swiss voters rejected a Green Party referendum to accelerate the phaseout of nuclear power (45.8% supported). The Swiss Federal Office of Energy (SFOE) is responsible for energy supply and energy use within the Federal Department of Environment, Transport, Energy and Communications (DETEC). The agency supports the 2000-watt society initiative to cut the nation's energy use by more than half by 2050. Transport The densest rail network in Europe spans and carries over 596 million passengers annually as of 2015. In 2015, each Swiss resident travelled on average by rail, more than any other European country. Virtually 100% of the network is electrified. 60% of the network is operated by the Swiss Federal Railways (SBB CFF FFS). Besides the second largest standard gauge railway company, BLS AG, two railways companies operate on narrow gauge networks: the Rhaetian Railway (RhB) in Graubünden, which includes some World Heritage lines, and the Matterhorn Gotthard Bahn (MGB), which co-operates with RhB the Glacier Express between Zermatt and St. Moritz/Davos. Switzerland operates the world's longest and deepest railway tunnel and the first flat, low-level route through the Alps, the Gotthard Base Tunnel, the largest part of the New Railway Link through the Alps (NRLA) project. Switzerland has a publicly managed, toll-free road network financed by highway permits as well as vehicle and gasoline taxes. The Swiss autobahn/autoroute system requires the annual purchase of a vignette (toll sticker)—for 40 Swiss francs—to use its roadways, including passenger cars and trucks. The Swiss autobahn/autoroute network stretches for and has one of the highest motorway densities in the world. Zurich Airport is Switzerland's largest international flight gateway; it handled 22.8 million passengers in 2012. The other international airports are Geneva Airport (13.9 million passengers in 2012), EuroAirport Basel Mulhouse Freiburg (located in France), Bern Airport, Lugano Airport, St. Gallen-Altenrhein Airport and Sion Airport. Swiss International Air Lines is the flag carrier. Its main hub is Zürich, but it is legally domiciled in Basel. Environment Switzerland has one of the best environmental records among developed nations. It is a signatory to the Kyoto Protocol. With Mexico and South Korea it forms the Environmental Integrity Group (EIG). The country is active in recycling and anti-littering programs and is one of the world's top recyclers, recovering 66% to 96%