Blackburn in context: Street-network sprawl trends

Blackburn in context

2.73.64.55.4<19751976–19901991–20052006–2020SNDi of street additions
2.73.64.55.4<19751976–19901991–20052006–2020SNDi of entire street network
BlackburnEngland (Region)United Kingdom (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Blackburn plotted against England and United Kingdom. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Blackburn's incremental SNDi fell from 5.77 to 4.4 between 1991-2005 and 2006-2020. In terms of the aggregate network, Blackburn ranked 39th out of 124 cities in England and 46th out of 143 in United Kingdom as of 2020.

New Street Additions (2006–2020)

SNDi value
4.4
Rank in United Kingdom
85th of 143
Rank in England
77th of 124

Entire Network (Aggregate)

SNDi value
3.37
Rank in United Kingdom
46th of 143
Rank in England
39th of 124

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

What about similarly populated cities?

345678<19751976–19901991–20052006–2020SNDi of street additions
345678<19751976–19901991–20052006–2020SNDi of entire street network
BlackburnAruppukkottaiCoonoor

While Aruppukkottai and Coonoor both built increasingly disconnected streets over time, Blackburn 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. Blackburn and Aruppukkottai have been growing further apart in their street-network character since 1975.