Lusaka is the capital and largest city of Zambia. It is one of the fastest-developing cities in southern Africa. Lusaka is in the southern part of the central plateau at an elevation of about 1,279 metres. As of 2019, the city's population was about 3.3 million, while the urban population is estimated at 2.5 million in 2018. Lusaka is the centre of both commerce and government in Zambia and connects to the country's four main highways heading north, south, east and west. English is the official language of the city administration, while Bemba, Tonga, Lenje, Soli, Nkoya, Lozi and Nyanja are the commonly spoken street languages.