Nagasaki in context: Street-network sprawl trends

Nagasaki in context

2.12.83.54.2<19751976–19901991–20052006–2020SNDi of street additions
2.12.83.54.2<19751976–19901991–20052006–2020SNDi of entire street network
NagasakiNaoasaki (Region)Japan (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Nagasaki plotted against Naoasaki and Japan. The SNDi of new construction in Nagasaki peaked in 1976-1990, compared to Naoasaki which followed a zig-zag trend with an overall increase and Japan which followed a zig-zag trend with an overall increase. Most recently, Nagasaki's incremental SNDi fell from 3.92 to 3.86 between 1991-2005 and 2006-2020. In terms of the aggregate network, Nagasaki ranked 3rd out of 4 cities in Naoasaki and 120th out of 135 in Japan as of 2020.

New Street Additions (2006–2020)

SNDi value
3.86
Rank in Japan
116th of 135
Rank in Naoasaki
3rd of 4

Entire Network (Aggregate)

SNDi value
3.0
Rank in Japan
120th of 135
Rank in Naoasaki
3rd of 4

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

What about similarly populated cities?

2.43.24<19751976–19901991–20052006–2020SNDi of street additions
2.43.24<19751976–19901991–20052006–2020SNDi of entire street network
NagasakiSuizhouVillavicencio

In new street additions, Nagasaki built increasingly disconnected streets from 1975 through 1976-1990, then improved, while Suizhou built increasingly connected streets from 1975 through 1991-2005, then shifted to more disconnected patterns and Villavicencio fluctuated in its street-construction patterns. For the full network, Nagasaki and Villavicencio both became progressively more disconnected, while Suizhou became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards. Notably, Nagasaki had a more sprawly network than Villavicencio in 1975 but the two have since reversed their relative ranking.