Cergy in context: Street-network sprawl trends

Cergy in context

2.533.54<19751976–19901991–20052006–2020SNDi of street additions
2.533.54<19751976–19901991–20052006–2020SNDi of entire street network
CergyIle-de-France (Region)France (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Cergy plotted against Île-de-France and France. The SNDi of new construction in Cergy rose steadily, compared to Île-de-France which peaked in 1976-1990 and France which peaked in 1991-2005. Most recently, Cergy's incremental SNDi rose from 3.17 to 3.22 between 1991-2005 and 2006-2020. In terms of the aggregate network, Cergy ranked 3rd out of 8 cities in Île-de-France and 49th out of 73 in France as of 2020.

New Street Additions (2006–2020)

SNDi value
3.22
Rank in France
39th of 73
Rank in Île-de-France
7th of 8

Entire Network (Aggregate)

SNDi value
2.79
Rank in France
49th of 73
Rank in Île-de-France
3rd of 8

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

What about similarly populated cities?

1.522.53<19751976–19901991–20052006–2020SNDi of street additions
1.522.53<19751976–19901991–20052006–2020SNDi of entire street network
CergyBielefeldNador

While Bielefeld and Nador both fluctuated in its street-construction patterns, Cergy built increasingly disconnected streets over time in new street additions. For the full street network, though, all three cities follow the same trend.