Tosu 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 Tosu plotted against Saga and Japan. The SNDi of new construction in Tosu peaked in 1991-2005, compared to Saga which peaked in 1976-1990 and Japan which followed a zig-zag trend with an overall increase. Most recently, Tosu's incremental SNDi fell from 2.09 to 1.91 between 1991-2005 and 2006-2020. In terms of the aggregate network, Tosu ranked 1st out of 3 cities in Saga and 33rd 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?

• Gangakhed, India
• Setúbal, Portugal
• Khash, Iran
• Pandaveswar, India
• Ayang, South Korea
• Novara, Italy

In new street additions, Tosu built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Gangakhed fluctuated in its street-construction patterns and Pandaveswar fluctuated in its street-construction patterns. For the full network, Tosu grew more disconnected from 1975 through 1991-2005, then improved, while Gangakhed became progressively more disconnected and Pandaveswar became progressively more connected. Tosu and Gangakhed have been growing further apart in their street-network character since 1975.