Botswana has  of railway lines,  of roads, and 92 airports, of which 12 have paved runways. The paved road network has almost entirely been constructed since independence in 1966. The national airline is Air Botswana, which flies domestically and to other countries in Africa. Botswana Railways is the national railway company, which forms a crucial link in the Southern African regional railway system. Botswana Railways offers rail-based transport facilities for moving a range of commodities for the mining sector and primary industries, as well as passenger-train services and dry ports.