Chicago in context: Street-network sprawl trends

Chicago in context

1.82.73.64.55.4<19751976–19901991–20052006–2020SNDi of street additions
1.82.73.64.55.4<19751976–19901991–20052006–2020SNDi of entire street network
ChicagoIllinois (Region)United States (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Chicago plotted against Illinois and United States. The SNDi of new construction in Chicago rose steadily, compared to Illinois which peaked in 1991-2005 and United States which peaked in 1991-2005. Most recently, Chicago's incremental SNDi rose from 3.68 to 3.77 between 1991-2005 and 2006-2020. In terms of the aggregate network, Chicago ranked 3rd out of 12 cities in Illinois and 61st out of 333 in United States as of 2020.

New Street Additions (2006–2020)

SNDi value
3.77
Rank in United States
112th of 333
Rank in Illinois
5th of 12

Entire Network (Aggregate)

SNDi value
2.21
Rank in United States
61st of 333
Rank in Illinois
3rd of 12

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
ChicagoMiamiXi'an

In new street additions, Chicago built increasingly disconnected streets over time, while Miami built increasingly disconnected streets from 1975 through 1991-2005, then improved and Xi'an fluctuated in its street-construction patterns. For the full street network, though, all three cities follow the same trend.