Nanjing in context: Street-network sprawl trends

Nanjing in context

2.433.64.2<19751976–19901991–20052006–2020SNDi of street additions
2.433.64.2<19751976–19901991–20052006–2020SNDi of entire street network
NanjingJiangsu (Region)China (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Nanjing plotted against Jiangsu and China. The SNDi of new construction in Nanjing peaked in 1991-2005, compared to Jiangsu which peaked in 1976-1990 and China which followed a zig-zag trend with an overall increase. Most recently, Nanjing's incremental SNDi fell from 3.4 to 3.37 between 1991-2005 and 2006-2020. In terms of the aggregate network, Nanjing ranked 64th out of 101 cities in Jiangsu and 1119th out of 1843 in China as of 2020.

New Street Additions (2006–2020)

SNDi value
3.37
Rank in China
1092nd of 1843
Rank in Jiangsu
67th of 101

Entire Network (Aggregate)

SNDi value
3.12
Rank in China
1119th of 1843
Rank in Jiangsu
64th of 101

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

What about similarly populated cities?

2.42.83.23.6<19751976–19901991–20052006–2020SNDi of street additions
2.42.83.23.6<19751976–19901991–20052006–2020SNDi of entire street network
NanjingChengduRiyadh

While Chengdu and Riyadh both built increasingly disconnected streets over time, Nanjing built increasingly disconnected streets from 1975 through 1991-2005, then improved in new street additions. For the full street network, though, all three cities follow the same trend. Nanjing and Chengdu have been growing further apart in their street-network character since 1975.