Calais in context: Street-network sprawl trends

Calais in context

2.43.244.8<19751976–19901991–20052006–2020SNDi of street additions
2.43.244.8<19751976–19901991–20052006–2020SNDi of entire street network
CalaisHauts-de-France (Region)France (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Calais plotted against Hauts-de-France and France. The SNDi of new construction in Calais rose steadily, compared to Hauts-de-France which peaked in 1991-2005 and France which peaked in 1991-2005. Most recently, Calais's incremental SNDi rose from 3.84 to 4.59 between 1991-2005 and 2006-2020. In terms of the aggregate network, Calais ranked 5th out of 10 cities in Hauts-de-France and 26th out of 73 in France as of 2020.

New Street Additions (2006–2020)

SNDi value
4.59
Rank in France
59th of 73
Rank in Hauts-de-France
9th of 10

Entire Network (Aggregate)

SNDi value
2.37
Rank in France
26th of 73
Rank in Hauts-de-France
5th of 10

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

What about similarly populated cities?

1.82.73.64.5<19751976–19901991–20052006–2020SNDi of street additions
1.82.73.64.5<19751976–19901991–20052006–2020SNDi of entire street network
CalaisEastleighBoli

In new street additions, Calais and Boli both built increasingly disconnected streets over time, while Eastleigh fluctuated in its street-construction patterns. For the full network, Calais and Eastleigh both became progressively more disconnected, while Boli became more connected from 1975 through 1991-2005, then grew more sprawly from 1991-2005 onwards. Calais and Boli have been converging in their street-network character since 1975.