Bologna in context: Street-network sprawl trends

Bologna in context

2.433.64.2<19751976–19901991–20052006–2020SNDi of street additions
2.433.64.2<19751976–19901991–20052006–2020SNDi of entire street network
BolognaEmilia-Romagna (Region)Italy (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Bologna plotted against Emilia-Romagna and Italy. The SNDi of new construction in Bologna followed a zig-zag trend with an overall increase, compared to Emilia-Romagna which peaked in 1991-2005 and Italy which peaked in 1991-2005. Most recently, Bologna's incremental SNDi rose from 2.99 to 3.17 between 1991-2005 and 2006-2020. In terms of the aggregate network, Bologna ranked 5th out of 10 cities in Emilia-Romagna and 33rd out of 88 in Italy as of 2020.

New Street Additions (2006–2020)

SNDi value
3.17
Rank in Italy
33rd of 88
Rank in Emilia-Romagna
5th of 10

Entire Network (Aggregate)

SNDi value
2.46
Rank in Italy
33rd of 88
Rank in Emilia-Romagna
5th of 10

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

What about similarly populated cities?

1.42.12.83.5<19751976–19901991–20052006–2020SNDi of street additions
1.42.12.83.5<19751976–19901991–20052006–2020SNDi of entire street network
BolognaMatamorosSaurimo

In new street additions, Bologna fluctuated in its street-construction patterns, while Matamoros built increasingly disconnected streets over time and Saurimo built increasingly connected streets from 1975 through 1991-2005, then shifted to more disconnected patterns. For the full network, Bologna and Matamoros both became progressively more disconnected, while Saurimo became progressively more connected. Bologna and Matamoros have been converging in their street-network character since 1975.