High Quality Content by WIKIPEDIA articles! Transport in the United Kingdom is facilitated with well-developed road, air, rail, and water networks. A radial road network totals 29,145 miles (46,904 km) of main roads, 2,173 miles (3,497 km) of motorways and 213,750 miles (344,000 km) of paved roads. The National Rail network of 10,072 route miles (16,116 km) in Great Britain and 189 route miles (303 route km) in Northern Ireland carries over 18,000 passenger and 1,000 freight trains daily. Urban rail networks are also well developed in London, Manchester, Birmingham, Edinburgh, Glasgow, Cardiff, Leeds and Liverpool. Heathrow Airport is the world's busiest international airport, and the UK has a considerable network of ports which received over 558 million tonnes of goods in 2003?2004.