Yatsushiro in context: Street-network sprawl trends

Yatsushiro in context

1.82.12.42.7<19751976–19901991–20052006–2020SNDi of street additions
1.82.12.42.7<19751976–19901991–20052006–2020SNDi of entire street network
YatsushiroKumamoto (Region)Japan (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Yatsushiro plotted against Kumamoto and Japan. The SNDi of new construction in Yatsushiro peaked in 1976-1990, compared to Kumamoto which followed a zig-zag trend with an overall increase and Japan which followed a zig-zag trend with an overall increase. Most recently, Yatsushiro's incremental SNDi fell from 2.03 to 1.85 between 1991-2005 and 2006-2020. In terms of the aggregate network, Yatsushiro ranked 1st out of 2 cities in Kumamoto and 47th out of 135 in Japan as of 2020.

New Street Additions (2006–2020)

SNDi value
1.85
Rank in Japan
14th of 135
Rank in Kumamoto
1st of 2

Entire Network (Aggregate)

SNDi value
2.07
Rank in Japan
47th of 135
Rank in Kumamoto
1st of 2

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

What about similarly populated cities?

1.82.73.64.5<19751976–19901991–20052006–2020SNDi of street additions
1.82.73.64.5<19751976–19901991–20052006–2020SNDi of entire street network
YatsushiroNew BussaFengqing County

In new street additions, Yatsushiro and Fengqing County both built increasingly disconnected streets from 1975 through 1976-1990, then improved, while New Bussa built increasingly disconnected streets over time. For the full network, Yatsushiro and Fengqing County both grew more disconnected from 1975 through 1976-1990, then improved, while New Bussa became progressively more disconnected. Notably, Yatsushiro had a more sprawly network than New Bussa in 1975 but the two have since reversed their relative ranking.