Birmingham in context: Street-network sprawl trends

Birmingham in context

23456<19751976–19901991–20052006–2020SNDi of street additions
23456<19751976–19901991–20052006–2020SNDi of entire street network
BirminghamAlabama (Region)United States (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Birmingham plotted against Alabama and United States. The SNDi of new construction in Birmingham followed a zig-zag trend with an overall increase, compared to Alabama which rose steadily and United States which peaked in 1991-2005. Most recently, Birmingham's incremental SNDi rose from 3.34 to 4.43 between 1991-2005 and 2006-2020. In terms of the aggregate network, Birmingham ranked 1st out of 4 cities in Alabama and 75th out of 333 in United States as of 2020.

New Street Additions (2006–2020)

SNDi value
4.43
Rank in United States
202nd of 333
Rank in Alabama
3rd of 4

Entire Network (Aggregate)

SNDi value
2.35
Rank in United States
75th of 333
Rank in Alabama
1st of 4

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

What about similarly populated cities?

2345<19751976–19901991–20052006–2020SNDi of street additions
2345<19751976–19901991–20052006–2020SNDi of entire street network
BirminghamChengjiangBukoba

In new street additions, Birmingham fluctuated in its street-construction patterns, while Chengjiang built increasingly disconnected streets from 1975 through 1976-1990, then improved and Bukoba built increasingly disconnected streets over time. For the full network, Birmingham and Bukoba both became progressively more disconnected, while Chengjiang grew more disconnected from 1975 through 1991-2005, then improved.