Koriyama in context: Street-network sprawl trends

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Koriyama plotted against Fukushima and Japan. The SNDi of new construction in Koriyama peaked in 1976-1990, compared to Fukushima which peaked in 1976-1990 and Japan which followed a zig-zag trend with an overall increase. Most recently, Koriyama's incremental SNDi fell from 2.83 to 2.17 between 1991-2005 and 2006-2020. In terms of the aggregate network, Koriyama ranked 1st out of 5 cities in Fukushima and 77th out of 135 in Japan as of 2020.

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

What about similarly populated cities?

• Gillingham, United Kingdom
• Mianwali, Pakistan
• Laksmipur, Nepal
• Dharashiv, India
• Cabanatuan, Philippines
• Urgench, Uzbekistan

In new street additions, Koriyama built increasingly disconnected streets from 1975 through 1976-1990, then improved, while Gillingham built increasingly disconnected streets from 1975 through 1991-2005, then improved and Dharashiv fluctuated in its street-construction patterns. Looking at the full network, Gillingham and Dharashiv both became progressively more disconnected, while Koriyama grew more disconnected from 1975 through 1991-2005, then improved. Koriyama and Dharashiv have been growing further apart in their street-network character since 1975.