The N12 Southern Bypass is a section of the Johannesburg Ring Road

Johannesburg Ring Road

The Johannesburg Ring Road is Africa's most famous beltway. It is made up of a subset of the freeways that circle the city of Johannesburg, South Africa and services the Greater Johannesburg Metropolitan Area. Construction on the Ring Road began in the late 1960s...

 located in the city of Johannesburg

Johannesburg

Johannesburg also known as Jozi, Jo'burg or Egoli, is the largest city in South Africa, by population. Johannesburg is the provincial capital of Gauteng, the wealthiest province in South Africa, having the largest economy of any metropolitan region in Sub-Saharan Africa...

, South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

. The freeway was the last section of the Ring Road to be built, with the final section opening in 1986. It was initially called the N13. From the west, the Southern Bypass begins at the Diepkloof Interchange, where it splits from the N1 freeway

N1 (South Africa)

The N1 is a South African National Route, running from Cape Town to Beit Bridge on the border with Zimbabwe. It is also the main road link between Johannesburg and Cape Town, and forms the first section of the famed Cape to Cairo Road....

. It ends at the Elands Interchange, where it merges with the N3 freeway

N3 (South Africa)

The N3 is a National Route in South Africa, connecting 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...

. The exists include the M1 Uncle Charlies Interchange (North Eastbound only), M17 Xavier Street, R556 Kliprivier Drive, M11 Comaro Road, R59 Reading Interchange, and R103 Voortrekker Road (Alberton).

As with the N1 Western Bypass

N1 Western Bypass (South Africa)

The Western Bypass is a section of the N1 and the Johannesburg Ring Road located in the city of Johannesburg, South Africa. The freeway was inially opened in 1975 as a route to avoid the city centre of Johannesburg and access for the western areas of the Witwatersrand. From the south, the Western...

, the freeway was built with concrete between Reading and Diepkloof and has always been three lanes wide in either direction, fanning out into four lanes at Reading. The freeway passes through a declared green belt

Green belt

A green belt or greenbelt is a policy and land use designation used in land use planning to retain areas of largely undeveloped, wild, or agricultural land surrounding or neighbouring urban areas. Similar concepts are greenways or green wedges which have a linear character and may run through an...

 area to the south of Johannesburg, which has prevented the construction of billboards

Billboard (advertising)

A billboard is a large outdoor advertising structure , typically found in high traffic areas such as alongside busy roads. Billboards present large advertisements to passing pedestrians and drivers...

along the roadside, a common practice in the city.