The N12 Southern Bypass is a section of the Johannesburg Ring Road that forms a beltway around the city of Johannesburg, South Africa, as part of the N12. The freeway was the last section of the Ring Road to be built, with the final section opening in 1986. As part of the old South African Freeways, It was initially called the N13.^[1][2][3][4] The entire Southern Bypass freeway was an e-toll highway (with open road tolling) from 3 December 2013^[5] to 11 April 2024.^[6][7]

Quick Facts National route N12, Route information ...

National route N12
Route information
Length	20.4 km (12.7 mi)
Existed	1986–present
Major junctions
West end	N1 Diepkloof Interchange
Major intersections	M1 Uncle Charlies Interchange M17 Xavier Street, Ridgeway M7 Kliprivier Drive, Suideroord M11 Comaro Street, Oakdene R59 Reading Interchange, Alberton R103 / M31 Voortrekker Road, Alberton N17 Elands Interchange, Germiston
east end	N3 Elands Interchange, Germiston
Location
Country	South Africa
Highway system
Numbered routes of South Africa

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From the west, the Southern Bypass begins at the Diepkloof Interchange, where it splits from the N1 freeway. It ends at the Elands Interchange, where it merges with the N3 freeway to be cosigned with it on the N3 Eastern Bypass northwards. The exits include the M1 Uncle Charlie's Interchange (north eastbound only), M17 Xavier Street, M7 Kliprivier Drive, M11 Comaro Road, R59 Reading Interchange, and R103/M31 Voortrekker Road (Alberton).

The N12 Southern Bypass, which cuts a concrete swath through the rocky hills of southern Johannesburg, is apparently very reminiscent of the freeways of Los Angeles, and together with Johannesburg's sunshine, renders a real Southern California feel to that part of the city.

As with the N1 Western Bypass, 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 area to the south of Johannesburg, which has prevented the construction of billboards along the roadside, a common practice in the city.^[8][9][10]