Supporting information (online component) for

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"A global assessment of street-network sprawl"

Barrington-Leigh and Millard-Ball

PLoS One, Nov 2019

"Global trends towards urban street-network sprawl"

Barrington-Leigh and Millard-Ball

Proceedings of the National Academy of Sciences, January 2020

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Here are the main papers and their two (long /detailed) Supplementary Information files:

• ``A global assessment of street-network sprawl'' PLoS ONE, 14(11): doi:10.1371/journal.pone.0210091, November 2019.

  We define a new, globally-comparable index of street-network sprawl, and map it for the entire planet. We define a classification of street network types for geographic grid cells. We provide qualitative and quantitative validations for our measures.

  Main paper (PDF)
  Supplementary information (PDF)
• ``Global trends towards urban street-network sprawl'' Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.1905232116 , January 2020.

  The pattern of new urban and residential roads represents an essentially permanent backbone that shapes new urban form and land use in the world’s cities. Thus, today’s choices on the connectivity of streets may restrict future resilience and lock in pathways of energy use and CO₂ emissions for a century or more. In contrast to the corrective trend observed in the USA, where streets have become more connected since the late 20th century, we find that most of the world is building ever-more disconnected “street-network sprawl.” A rapid policy response, including regulation and pricing tools, is needed to avoid further costly lock-in during this current, final phase of the urbanization process.

  Main paper (PDF)
  Supplementary information (PDF)

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Our data are available in an interactive online map, Sprawlmap.org

There is a (prospectively) Frequently Asked Questions page for the map web site.

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Open data

Our results are entirely reproducible using open access data, including OpenStreetMap.

There are also a lot more data displayed in various ways in the Supplementary Information PDFs (above).

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Open source code

The entire code base for server setup, data preparation, pre-processing, computation, and analysis for these two research papers is available under a GNU open source license for use by anyone. The code is in Python and SQL. It relies on a PostGIS server and was used with powerful hardware. This entire research project was carried out using open source operating systems, programming languages, manuscript preparation software, etc.

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Where does my country / city rank?

You can explore SNDi listings of 200 cities and most countries in sortable tables, here:

• Cities
• Countries

You can also download the data using the link at the top of each table.

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Some graphics and animations

Here's Figure 1 from PNAS 2020, showing our sprawl measure for recently-constructed streets around the world. The inset shows the distribution of our sprawl measure in different time periods

Here's Figure 2 from PNAS 2020, showing some broad, regional, and global trends:

See the papers (and SIs) for more images.

You can make animations yourself at the level of regions or streets, using our interactive online map, Sprawlmap.org.

	Evolution of development style over time: country-level
	Evolution of development style over time: province/state-level
	Evolution of development style over time: sub-sub-national
	Sainte Therese, QC, Canada. Explore in our dynamic map
	Terrebonne, QC, Canada. Explore in our dynamic map

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Some press

• McGill's press release, 14 January 2020
• NewScientist, 12 December 2019

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