Christchurch in context: Street-network sprawl trends

Christchurch in context

2.43.244.8<19751976–19901991–20052006–2020SNDi of street additions
2.43.244.8<19751976–19901991–20052006–2020SNDi of entire street network
ChristchurchCanterbury (Region)New Zealand (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Christchurch plotted against Canterbury and New Zealand. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Christchurch's incremental SNDi fell from 3.58 to 2.48 between 1991-2005 and 2006-2020. In terms of the aggregate network, Christchurch ranked 1st out of 1 cities in Canterbury and 2nd out of 9 in New Zealand as of 2020.

New Street Additions (2006–2020)

SNDi value
2.48
Rank in New Zealand
1st of 9
Rank in Canterbury
1st of 1

Entire Network (Aggregate)

SNDi value
2.68
Rank in New Zealand
2nd of 9
Rank in Canterbury
1st of 1

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

What about similarly populated cities?

23456<19751976–19901991–20052006–2020SNDi of street additions
23456<19751976–19901991–20052006–2020SNDi of entire street network
ChristchurchNashvilleKolwezi

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