A dual carriageway (BrE) or a divided highway (AmE) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, etc., rather than dual carriageways.
The N3 is a national route in South Africa that connects Johannesburg and Durban, respectively South Africa's largest and third-largest cities. Johannesburg is the financial and commercial heartland of South Africa, while Durban is South Africa's key port and one of the busiest ports in the Southern Hemisphere and is also a holiday destination. Durban is the port through which Johannesburg imports and exports most of its goods. As a result, the N3 is a very busy highway and has a high volume of traffic.
The N1 is a national route in South Africa that runs from Cape Town through Bloemfontein, Johannesburg, Pretoria and Polokwane to Beit Bridge on the border with Zimbabwe. It forms the first section of the famed Cape to Cairo Road.
The R55 is a north-south provincial route in Gauteng, South Africa that connects Sandton with Pretoria. It passes Woodmead, Kyalami, Olievenhoutbosch, Heuweloord, Sunderland Ridge, Erasmia, Laudium/Claudius, West Park, the Daspoort Tunnel and Danville. It connects with the M1, N14, and R80 highways. It is also designated as the P66-1 and K71 by the Gauteng Provincial Government.
The R75 is a provincial route in Eastern Cape, South Africa that connects Graaff-Reinet with Gqeberha via Despatch, Kariega and Jansenville.
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The N2 is a national route in South Africa that runs from Cape Town through George, Gqeberha, East London, Mthatha, Port Shepstone and Durban to Ermelo. It is the main highway along the Indian Ocean coast of the country. Its current length of 2,255 kilometres (1,401 mi) makes it the longest numbered route in South Africa.
A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway, and expressway. Other similar terms include throughway or thruway and parkway. Some of these may be limited-access highways, although this term can also refer to a class of highways with somewhat less isolation from other traffic.
The Walvis Bay-Ndola-Lubumbashi Development Road runs from Walvis Bay, through Rundu in north eastern Namibia, along the Caprivi Strip to Katima Mulilo on the Zambezi River, which forms the border between Namibia and Zambia. The Katima Mulilo Bridge spans the river to the Zambian town of Sesheke from where a road runs to Livingstone, joining the main north–south highway to Lusaka, connecting onwards to the Copperbelt.
The M5 is an expressway in the City of Cape Town Metropolitan Municipality, South Africa. It connects Milnerton on the Western Seaboard in the north to Muizenberg in the south, and crosses both the N1 and the N2. For part of its length, from the N1 interchange to Plumstead, it is a limited-access freeway (motorway). From Mowbray to Muizenberg it is parallel to the M4 Main Road.
The N12 is a national route in South Africa which runs from George through Beaufort West, Kimberley, Klerksdorp and Johannesburg to eMalahleni.
The N4 is a national route in South Africa that runs from Skilpadshek on the Botswana border, past Rustenburg, Pretoria, eMalahleni and Mbombela, to Komatipoort on the Mozambique border. The entire route is a toll road.
The Trans-Kalahari Corridor is a paved highway corridor that provides a direct route from the port of Walvis Bay and Windhoek in central Namibia, through Botswana, to Pretoria in Gauteng province in South Africa. It initially cost approximately 850 million Namibian dollars and was officially opened in 1998.
The Trans-African Highway network comprises transcontinental road projects in Africa being developed by the United Nations Economic Commission for Africa (UNECA), the African Development Bank (ADB), and the African Union in conjunction with regional international communities. They aim to promote trade and alleviate poverty in Africa through highway infrastructure development and the management of road-based trade corridors. The total length of the nine highways in the network is 56,683 km (35,221 mi).
The Tripoli–Cape Town Highway or TAH 3 is Trans-African Highway 3 in the transcontinental road network being developed by the United Nations Economic Commission for Africa (UNECA), the African Development Bank (AfDB), and the African Union. The route has a length of 10,808 km (6,716 mi) and has the longest missing links and requires the most new road construction.
The M7, also named Jakes Gerwel Drive, is a limited-access road and metropolitan route in the City of Cape Town, South Africa. It connects Acacia Park with Rocklands on the False Bay Coast via the Cape Flats.
The B1 is a national highway of Namibia, and is the country's longest and most significant road, running the length of the country from south to north. It connects Noordoewer in the south on the South African border with Oshikango in the north on the Angolan border via Namibia's capital city Windhoek.
The N14 is a national route in South Africa which runs from Springbok in the Northern Cape to Pretoria in Gauteng. It passes through Upington, Kuruman, Vryburg, Krugersdorp and Centurion. The section between Pretoria and Krugersdorp is maintained by the Gauteng Provincial government and is also designated the P158.
The N17 is a national route in South Africa which runs from Johannesburg to Oshoek (Ngwenya) on the border with Eswatini. It passes through Springs, Bethal and Ermelo.
The A1 is a national highway in Namibia. The 76 kilometres (47 mi) stretch of road between Windhoek and Okahandja is the only A-rated road in Namibia. Consisting of freeway for its entire length, it came into existence in 2017 when freeway sections of the B1 were redesignated A1 in accordance with new standards of the Roads Authority Namibia. The entirety of the A1 forms part of the Trans-Kalahari Corridor and, together with the B1, also forms part of the Tripoli-Cape Town Highway.
N1 in Cape Town 
N14 at Springbok 
B1 at the Namibian border at Vioolsdrif 
