Perth in context: Street-network sprawl trends

Perth in context

2.83.54.24.9<19751976–19901991–20052006–2020SNDi of street additions
2.83.54.24.9<19751976–19901991–20052006–2020SNDi of entire street network
PerthWestern Australia (Region)Australia (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Perth plotted against Western Australia and Australia. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Perth's incremental SNDi fell from 3.45 to 2.4 between 1991-2005 and 2006-2020. In terms of the aggregate network, Perth ranked 2nd out of 4 cities in Western Australia and 7th out of 35 in Australia as of 2020.

New Street Additions (2006–2020)

SNDi value
2.4
Rank in Australia
4th of 35
Rank in Western Australia
2nd of 4

Entire Network (Aggregate)

SNDi value
2.92
Rank in Australia
7th of 35
Rank in Western Australia
2nd of 4

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

What about similarly populated cities?

2345<19751976–19901991–20052006–2020SNDi of street additions
2345<19751976–19901991–20052006–2020SNDi of entire street network
PerthManaguaHiroshima

In new street additions, Perth built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Managua built increasingly disconnected streets over time and Hiroshima fluctuated in its street-construction patterns. Looking at the full network, Managua and Hiroshima both became progressively more disconnected, while Perth grew more disconnected from 1975 through 1991-2005, then improved. Notably, Perth had a more sprawly network than Managua in 1975 but the two have since reversed their relative ranking.