Liuyang in context: Street-network sprawl trends

Liuyang in context

2.43.244.8<19751976–19901991–20052006–2020SNDi of street additions
2.43.244.8<19751976–19901991–20052006–2020SNDi of entire street network
LiuyangHunan (Region)China (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Liuyang plotted against Hunan and China. The SNDi of new construction in Liuyang peaked in 1976-1990, compared to Hunan which peaked in 1976-1990 and China which followed a zig-zag trend with an overall increase. Most recently, Liuyang's incremental SNDi fell from 3.9 to 3.27 between 1991-2005 and 2006-2020. In terms of the aggregate network, Liuyang ranked 72nd out of 89 cities in Hunan and 1497th out of 1843 in China as of 2020.

New Street Additions (2006–2020)

SNDi value
3.27
Rank in China
1031st of 1843
Rank in Hunan
53rd of 89

Entire Network (Aggregate)

SNDi value
3.82
Rank in China
1497th of 1843
Rank in Hunan
72nd of 89

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

What about similarly populated cities?

2.43.244.8<19751976–19901991–20052006–2020SNDi of street additions
2.43.244.8<19751976–19901991–20052006–2020SNDi of entire street network
LiuyangSanmingKumba

In new street additions, Liuyang built increasingly disconnected streets from 1975 through 1976-1990, then improved, while Sanming fluctuated in its street-construction patterns and Kumba built increasingly disconnected streets over time. Looking at the full network, Sanming and Kumba both became progressively more disconnected, while Liuyang grew more disconnected from 1975 through 1991-2005, then improved. Notably, Liuyang had a more connected network than Sanming in 1975 but the two have since reversed their relative ranking.