Sendai in context: Street-network sprawl trends

Sendai in context

22.42.83.23.6<19751976–19901991–20052006–2020SNDi of street additions
22.42.83.23.6<19751976–19901991–20052006–2020SNDi of entire street network
SendaiMiyagi (Region)Japan (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Sendai plotted against Miyagi and Japan. The SNDi of new construction in Sendai peaked in 1976-1990, compared to Miyagi which peaked in 1976-1990 and Japan which followed a zig-zag trend with an overall increase. Most recently, Sendai's incremental SNDi fell from 2.95 to 2.61 between 1991-2005 and 2006-2020. In terms of the aggregate network, Sendai ranked 3rd out of 4 cities in Miyagi and 112th out of 135 in Japan as of 2020.

New Street Additions (2006–2020)

SNDi value
2.61
Rank in Japan
68th of 135
Rank in Miyagi
3rd of 4

Entire Network (Aggregate)

SNDi value
2.84
Rank in Japan
112th of 135
Rank in Miyagi
3rd of 4

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

What about similarly populated cities?

1.82.433.6<19751976–19901991–20052006–2020SNDi of street additions
1.82.433.6<19751976–19901991–20052006–2020SNDi of entire street network
SendaiKitakyushuTurin

In new street additions, Sendai and Turin both built increasingly disconnected streets from 1975 through 1976-1990, then improved, while Kitakyushu fluctuated in its street-construction patterns. Looking at the full network, Kitakyushu and Turin both became progressively more disconnected, while Sendai grew more disconnected from 1975 through 1991-2005, then improved.