South Africa
What exactly constitutes the spatial extent of the city? For these aggregations, we used the Global Human Settlement Layer Urban Center Database (GHS-UCDB) to define the boundaries of the city. These cities -- or urban centers -- cover areas that are densely populated and built-up, and so may extend beyond the spatial borders of these cities that we may be familiar with. The GHS area is shaded in blue.
View South Africa on the sprawlmap
Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in South Africa as of 2014, the overall level of street-network sprawl is 3.67, which is highly disconnected.
Trends in street network construction: The SNDis of street construction for the respective time periods are 3.06, 3.79, 3.7 and 4.24. Disconnectivity in street construction in South Africa follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 2001-2014.
Quantity of street network construction: The street network in South Africa spans a total of 406614 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 4.24, which is highly disconnected.
Effect on the aggregate network: New construction in each period adds to the total stock of streets, but does not change streets that have already been built. Therefore, it has a limited effect on the street network as a whole. The SNDis of the aggregate street network in the respective time periods are 3.06, 3.48, 3.53 and 3.67. Overall, the SNDi of the aggregate street network has risen: the street network in South Africa has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.42 points, but between 1991-2000 and 2001-2014, it rose by just 0.14.
The level of street-network sprawl in new development in South Africa followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in South Africa, we can consider three of its most populous regions: Gauteng, Western Cape and KwaZulu-Natal. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Gauteng rose steadily. The level of street-network sprawl in new development in Western Cape peaked in 1991-2000. The level of street-network sprawl in new development in KwaZulu-Natal rose steadily.
How do development practices in South Africa fare in comparison to others in the world? Most recently in 2001-2014, street construction in South Africa was the 81st-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, street construction in South Africa has become more connected. South Africa ranked 64th in 1975, 58th in 1976-1990, 96th in 1991-2000 and 81st in 2001-2014.
The largest city in South Africa is Johannesburg, with a population of 6516100 people. Taking into account the entire (i.e. aggregate) street network in Johannesburg as of 2014, the overall level of street-network sprawl is 3.55, which is highly disconnected. The level of street-network sprawl in new development in Johannesburg rose steadily.
As of 2014, the city with the most disconnected street network in South Africa is Midrand with an SNDi of 6.97, which is highly disconnected. Conversely, the most connected city is Naas with an SNDi of 1.48, which is relatively well-connected. See trends for these cities: Naas, Midrand
The level of street-network sprawl in the aggregate network in South Africa rose steadily. To get a sense of how the aggregate street network has changed in South Africa, we can consider three of its most populous regions: Gauteng, Western Cape and KwaZulu-Natal. Disconnectivity in the most populous cities in South Africa follow the same country trend.
To date, South Africa is the 66th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, the street network in South Africa has become more connected. South Africa ranked 64th in 1975, 62nd in 1976-1990, 62nd in 1991-2000 and 66th in 2001-2014.
The largest city in South Africa is Johannesburg, with a population of 6516100 people. Taking into account the entire (i.e. aggregate) street network in Johannesburg as of 2014, the overall level of street-network sprawl is 3.55, which is highly disconnected. The level of street-network sprawl in the aggregate network in Johannesburg rose steadily.