Songyang County in context: Street-network sprawl trends

Songyang County in context

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
Songyang CountyZhejiang (Region)China (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Songyang County plotted against Zhejiang and China. The SNDi of new construction in Songyang County peaked in 1976-1990, compared to Zhejiang which followed a zig-zag trend with an overall increase and China which followed a zig-zag trend with an overall increase. Most recently, Songyang County's incremental SNDi fell from 2.26 to 2.22 between 1991-2005 and 2006-2020. In terms of the aggregate network, Songyang County ranked 16th out of 116 cities in Zhejiang and 310th out of 1843 in China as of 2020.

New Street Additions (2006–2020)

SNDi value
2.22
Rank in China
351st of 1843
Rank in Zhejiang
19th of 116

Entire Network (Aggregate)

SNDi value
2.15
Rank in China
310th of 1843
Rank in Zhejiang
16th of 116

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
Songyang CountyDachepalliAuburn

In new street additions, Songyang County and Auburn both built increasingly disconnected streets from 1975 through 1976-1990, then improved, while Dachepalli built increasingly disconnected streets over time. For the full street network, though, all three cities follow the same trend.