Ashburn in context: Street-network sprawl trends

Ashburn in context

3456<19751976–19901991–20052006–2020SNDi of street additions
3456<19751976–19901991–20052006–2020SNDi of entire street network
AshburnVirginia (Region)United States (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Ashburn plotted against Virginia and United States. The SNDi of new construction in Ashburn peaked in 1976-1990, compared to Virginia which peaked in 1991-2005 and United States which peaked in 1991-2005. Most recently, Ashburn's incremental SNDi fell from 4.71 to 4.62 between 1991-2005 and 2006-2020. In terms of the aggregate network, Ashburn ranked 7th out of 11 cities in Virginia and 292nd out of 333 in United States as of 2020.

New Street Additions (2006–2020)

SNDi value
4.62
Rank in United States
221st of 333
Rank in Virginia
5th of 11

Entire Network (Aggregate)

SNDi value
4.71
Rank in United States
292nd of 333
Rank in Virginia
7th of 11

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

What about similarly populated cities?

23456<19751976–19901991–20052006–2020SNDi of street additions
23456<19751976–19901991–20052006–2020SNDi of entire street network
AshburnXiaochikouDhlail

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