Pretoria in context: Street-network sprawl trends

Pretoria in context

2.73.64.55.4<19751976–19901991–20052006–2020SNDi of street additions
2.73.64.55.4<19751976–19901991–20052006–2020SNDi of entire street network
PretoriaGauteng (Region)South Africa (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Pretoria plotted against Gauteng and South Africa. The SNDi of new construction in Pretoria peaked in 1991-2005, compared to Gauteng which peaked in 1991-2005 and South Africa which rose steadily. Most recently, Pretoria's incremental SNDi fell from 5.93 to 5.88 between 1991-2005 and 2006-2020. In terms of the aggregate network, Pretoria ranked 13th out of 14 cities in Gauteng and 73rd out of 81 in South Africa as of 2020.

New Street Additions (2006–2020)

SNDi value
5.88
Rank in South Africa
68th of 81
Rank in Gauteng
12th of 14

Entire Network (Aggregate)

SNDi value
4.9
Rank in South Africa
73rd of 81
Rank in Gauteng
13th of 14

Rankings go from most connected to most disconnected — rank 1 is the most connected.

What about similarly populated cities?

3.54.24.95.6<19751976–19901991–20052006–2020SNDi of street additions
3.54.24.95.6<19751976–19901991–20052006–2020SNDi of entire street network
PretoriaTijuanaMecca

In new street additions, Pretoria built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Tijuana fluctuated in its street-construction patterns and Mecca built increasingly disconnected streets from 1975 through 1976-1990, then improved. For the full street network, though, all three cities follow the same trend. Notably, Pretoria had a more connected network than Tijuana in 1975 but the two have since reversed their relative ranking.