Dunedin in context: Street-network sprawl trends

Dunedin in context

1.82.73.64.55.4<19751976–19901991–20052006–2020SNDi of street additions
1.82.73.64.55.4<19751976–19901991–20052006–2020SNDi of entire street network
DunedinOtago (Region)New Zealand (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Dunedin plotted against Otago and New Zealand. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Dunedin's incremental SNDi fell from 4.46 to 3.43 between 1991-2005 and 2006-2020. In terms of the aggregate network, Dunedin ranked 1st out of 1 cities in Otago and 1st out of 9 in New Zealand as of 2020.

New Street Additions (2006–2020)

SNDi value
3.43
Rank in New Zealand
3rd of 9
Rank in Otago
1st of 1

Entire Network (Aggregate)

SNDi value
2.37
Rank in New Zealand
1st of 9
Rank in Otago
1st of 1

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

What about similarly populated cities?

1.62.43.24<19751976–19901991–20052006–2020SNDi of street additions
1.62.43.24<19751976–19901991–20052006–2020SNDi of entire street network
DunedinBaoshanBiala

In new street additions, Dunedin built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Baoshan fluctuated in its street-construction patterns and Biala built increasingly disconnected streets over time. For the full street network, though, all three cities follow the same trend. Dunedin and Biala have been growing further apart in their street-network character since 1975.