Napa in context: Street-network sprawl trends

Napa in context

33.64.24.8<19751976–19901991–20052006–2020SNDi of street additions
33.64.24.8<19751976–19901991–20052006–2020SNDi of entire street network
NapaCalifornia (Region)United States (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Napa plotted against California and United States. The SNDi of new construction in Napa peaked in 1976-1990, compared to California which peaked in 1976-1990 and United States which peaked in 1991-2005. Most recently, Napa's incremental SNDi fell from 4.4 to 4.39 between 1991-2005 and 2006-2020. In terms of the aggregate network, Napa ranked 20th out of 60 cities in California and 185th out of 333 in United States as of 2020.

New Street Additions (2006–2020)

SNDi value
4.39
Rank in United States
200th of 333
Rank in California
42nd of 60

Entire Network (Aggregate)

SNDi value
3.4
Rank in United States
185th of 333
Rank in California
20th of 60

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

What about similarly populated cities?

012345<19751976–19901991–20052006–2020SNDi of street additions
012345<19751976–19901991–20052006–2020SNDi of entire street network
NapaHengshanTirora

While Hengshan and Tirora both built increasingly disconnected streets over time, Napa built increasingly disconnected streets from 1975 through 1976-1990, then improved in new street additions. For the full street network, though, all three cities follow the same trend. Napa and Hengshan have been converging in their street-network character since 1975.