Nampa in context: Street-network sprawl trends

Nampa in context

2.73.64.5<19751976–19901991–20052006–2020SNDi of street additions
2.73.64.5<19751976–19901991–20052006–2020SNDi of entire street network
NampaIdaho (Region)United States (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Nampa plotted against Idaho and United States. All three follow the same trend in new construction, suggesting a shared regional pattern of development. Most recently, Nampa's incremental SNDi fell from 4.54 to 4.13 between 1991-2005 and 2006-2020. In terms of the aggregate network, Nampa ranked 2nd out of 2 cities in Idaho and 210th out of 333 in United States as of 2020.

New Street Additions (2006–2020)

SNDi value
4.13
Rank in United States
167th of 333
Rank in Idaho
2nd of 2

Entire Network (Aggregate)

SNDi value
3.58
Rank in United States
210th of 333
Rank in Idaho
2nd of 2

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
NampaChesterSinwon

In new street additions, Nampa and Chester both built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Sinwon built increasingly disconnected streets over time. For the full street network, though, all three cities follow the same trend. Notably, Nampa had a more connected network than Chester in 1975 but the two have since reversed their relative ranking.