Edinburgh is a major transport hub in east central Scotland and is at the centre of a multi-modal transport network with road, rail and air communications connecting the city with the rest of Scotland and internationally. Transport is an area under the control of the Scottish Parliament and Scottish Government who have the statutory power to control, fund and regulate transport projects of national importance within the city. Transport for Edinburgh is The City of Edinburgh Council's executive body responsible for the development of all transport projects within the city, and it brings a number of key transport providers together under one umbrella. Public transport in Edinburgh is generally extensive and efficient, but problems such as traffic congestion and the delivery of key transport projects in the city are a prevailing concern. Airport Edinburgh Airport is to the west of the city centre, on the A8 trunk road, and is the principal international gateway to the city, as well as the busiest airport in Scotland. It is owned and operated by Global Infrastructure Partners. The airport serves a wide range of domestic and an expanding number of European, transatlantic and Middle East destinations, handling over 12 million passengers per year. The main terminal building was built in 1977 by the Edinburgh architect Robert Matthew, and was substantially extended and modernised in the late 1990s. A £14m project to construct a new international pier, further increasing capacity, was completed in 2006. A master plan for the growth of the airport was published in May 2005 indicating that the main terminal building will need to be increased in size, and that new aircraft hangars, maintenance facilities, and cargo handling facilities will need to be constructed. The possibility of a second runway built on land to the north of the current airfield, has been mooted, to cope with the forecast growth in air traffic. A new air traffic control tower was opened in October 2005. Currently the airport is connected to the city centre by a dedicated bus link operating from the main terminal building to Waverley Bridge and a tram link from the airport to the city centre which opened in May 2014. Bus transport Bus services Buses are the main means of public transport in Edinburgh. There is an extensive bus network, covering all parts of the city, its suburbs and the surrounding city region. Edinburgh is widely regarded as having