Lyon in context: Street-network sprawl trends

Lyon 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
LyonAuvergne-Rhone-Alpes (Region)France (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Lyon plotted against Auvergne-Rhône-Alpes and France. The SNDi of new construction in Lyon peaked in 1976-1990, compared to Auvergne-Rhône-Alpes which peaked in 1991-2005 and France which peaked in 1991-2005. Most recently, Lyon's incremental SNDi fell from 4.3 to 3.12 between 1991-2005 and 2006-2020. In terms of the aggregate network, Lyon ranked 5th out of 8 cities in Auvergne-Rhône-Alpes and 52nd out of 73 in France as of 2020.

New Street Additions (2006–2020)

SNDi value
3.12
Rank in France
32nd of 73
Rank in Auvergne-Rhône-Alpes
1st of 8

Entire Network (Aggregate)

SNDi value
2.86
Rank in France
52nd of 73
Rank in Auvergne-Rhône-Alpes
5th of 8

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

What about similarly populated cities?

1.62.43.24<19751976–19901991–20052006–2020SNDi of street additions
1.62.43.24<19751976–19901991–20052006–2020SNDi of entire street network
LyonYekaterinburgPrague

While Yekaterinburg and Prague both built increasingly disconnected streets over time, Lyon 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.