Transport in Tanzania includes road, rail, air and water networks. The road network is 86,472 kilometres (53,731 mi) long, of which 12,786 kilometres (7,945 mi) is classified as trunk road and 21,105 kilometres (13,114 mi) as regional road. The rail network consists of 3,682 kilometres (2,288 mi) of track. Commuter rail service is in Dar es Salaam only. There are 28 airports, with Julius Nyerere International being the largest and the busiest. Ferries connect Mainland Tanzania with the islands of Zanzibar. Several other ferries are active on the countries' rivers and lakes.
The Tanzania National Roads Agency (TANROADS) - an Executive Agency under the Ministry of Works, Transport and Communications - came into operation in July 2000 and is the agency responsible for the maintenance and development of the trunk and regional road network in Mainland Tanzania. The total classified road network in Mainland Tanzania was estimated to be 86,472 kilometres (53,731 mi) based on the Road Act 2007. The Ministry of Works through TANROADS is managing the national road network of about 33,891 kilometres (21,059 mi), comprising 12,786 kilometres (7,945 mi) of trunk road and 21,105 kilometres (13,114 mi) of regional road. The remaining network of about 53,460 kilometres (33,220 mi) of urban, district and feeder roads is under the responsibility of the Prime Minister’s Office Regional Administration and Local Government (PMO-RALG).
In 2007 there were 91,049 kilometres (56,575 mi) of roads, of which including 6,578 kilometres (4,087 mi) was paved. The road network ranked 51st worldwide by length.
Most of the trunk roads in Tanzania are marked by numbers following the two-tier number system with prefixes A- and B-, as is practiced in the rest of East Africa. Following is the list of Tanzanian trunk roads.
The Cairo-Cape Town Highway, Highway 4 in the Trans-African Highway network, runs between the northern town of Namanga on the Kenyan border and the Zambian border town of Tunduma in the southwest, via Arusha, Dodoma, Iringa, and Mbeya. The section between the entrance to Tarangire National Park and Iringa is unpaved and can be difficult when raining, especially north of Kondoa. A longer eastern route from Arusha to Iringa via Moshi and Morogoro is paved. This route is 921 kilometres (572 mi) versus 689 kilometres (428 mi) for the Arusha-Dodoma-Iringa route.