Oyama in context: Street-network sprawl trends

Oyama in context

1.622.42.8<19751976–19901991–20052006–2020SNDi of street additions
1.622.42.8<19751976–19901991–20052006–2020SNDi of entire street network
OyamaTochigi (Region)Japan (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Oyama plotted against Tochigi and Japan. While Tochigi and Japan both followed a zig-zag trend with an overall increase, Oyama's new street additions followed a zig-zag trend with an overall increase. Most recently, Oyama's incremental SNDi rose from 1.68 to 2.59 between 1991-2005 and 2006-2020. In terms of the aggregate network, Oyama ranked 1st out of 4 cities in Tochigi and 20th out of 135 in Japan as of 2020.

New Street Additions (2006–2020)

SNDi value
2.59
Rank in Japan
64th of 135
Rank in Tochigi
3rd of 4

Entire Network (Aggregate)

SNDi value
1.69
Rank in Japan
20th of 135
Rank in Tochigi
1st of 4

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
OyamaQingtianKattumannarkoil

In new street additions, Oyama fluctuated in its street-construction patterns, while Qingtian built increasingly disconnected streets over time and Kattumannarkoil built increasingly connected streets from 1975 through 1991-2005, then shifted to more disconnected patterns. For the full network, Oyama and Qingtian both became progressively more disconnected, while Kattumannarkoil became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards.