Portsmouth in context: Street-network sprawl trends
Portsmouth in context
The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Portsmouth plotted against England and United Kingdom. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Portsmouth's incremental SNDi fell from 4.61 to 3.54 between 1991-2005 and 2006-2020. In terms of the aggregate network, Portsmouth ranked 75th out of 124 cities in England and 83rd out of 143 in United Kingdom as of 2020.
New Street Additions (2006–2020)
- SNDi value
- 3.54
- Rank in United Kingdom
- 35th of 143
- Rank in England
- 31st of 124
Entire Network (Aggregate)
- SNDi value
- 3.71
- Rank in United Kingdom
- 83rd of 143
- Rank in England
- 75th of 124
Rankings go from most connected to most disconnected — rank 1 is the most connected.
What about similarly populated cities?
In new street additions, Portsmouth built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Mỹ Tho built increasingly disconnected streets over time and Bi'r Rubak fluctuated in its street-construction patterns. For the full network, Portsmouth grew more disconnected from 1975 through 1991-2005, then improved, while Mỹ Tho became progressively more disconnected and Bi'r Rubak fluctuated in connectivity. Portsmouth and Mỹ Tho have been growing further apart in their street-network character since 1975.