St Albans in context: Street-network sprawl trends

St Albans in context

2.83.54.24.9<19751976–19901991–20052006–2020SNDi of street additions
2.83.54.24.9<19751976–19901991–20052006–2020SNDi of entire street network
St AlbansEngland (Region)United Kingdom (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with St Albans plotted against England and United Kingdom. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, St Albans's incremental SNDi fell from 4.72 to 2.71 between 1991-2005 and 2006-2020. In terms of the aggregate network, St Albans ranked 63rd out of 124 cities in England and 71st out of 143 in United Kingdom as of 2020.

New Street Additions (2006–2020)

SNDi value
2.71
Rank in United Kingdom
7th of 143
Rank in England
7th of 124

Entire Network (Aggregate)

SNDi value
3.58
Rank in United Kingdom
71st of 143
Rank in England
63rd of 124

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

What about similarly populated cities?

2468<19751976–19901991–20052006–2020SNDi of street additions
2468<19751976–19901991–20052006–2020SNDi of entire street network
St AlbansSerui KotaLingchuan

In new street additions, St Albans built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Serui Kota built increasingly disconnected streets over time and Lingchuan fluctuated in its street-construction patterns. For the full network, St Albans grew more disconnected from 1975 through 1991-2005, then improved, while Serui Kota became progressively more disconnected and Lingchuan fluctuated in connectivity. Notably, St Albans had a more sprawly network than Serui Kota in 1975 but the two have since reversed their relative ranking.