Iwakuni in context: Street-network sprawl trends

Iwakuni 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
IwakuniYamaguchi (Region)Japan (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Iwakuni plotted against Yamaguchi and Japan. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Iwakuni's incremental SNDi rose from 4.21 to 4.73 between 1991-2005 and 2006-2020. In terms of the aggregate network, Iwakuni ranked 4th out of 5 cities in Yamaguchi and 127th out of 135 in Japan as of 2020.

New Street Additions (2006–2020)

SNDi value
4.73
Rank in Japan
130th of 135
Rank in Yamaguchi
5th of 5

Entire Network (Aggregate)

SNDi value
3.25
Rank in Japan
127th of 135
Rank in Yamaguchi
4th of 5

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
IwakuniMajenangSircilla

In new street additions, Iwakuni and Sircilla both fluctuated in its street-construction patterns, while Majenang built increasingly disconnected streets over time. For the full network, Iwakuni and Majenang both became progressively more disconnected, while Sircilla fluctuated in connectivity. Iwakuni and Majenang have been growing further apart in their street-network character since 1975.