What is Street-network Sprawl?
Street-network Sprawl is a way to measure urban sprawl, worldwide, through the connectedness of the streets. Less sprawl means more connected, more walkable streets. We calculate street-network sprawl for every mapped street on Earth.
Why is Street-network Sprawl important?
The street network is permanent, and its connectivity affects the livability and environmental footprint of cities for decades and centuries to come. In places with more connected streets, residents drive less and walk more. Sprawl is associated with worse outcomes for health, the environment, overconsumption, social segregation, and equity.
How do I use the site?
Starting with the 'Globe' view, you can click on a country to enter the 'Zoomable map' mode. Keep zooming in to see more detail. Eventually you will see the individual roads.
Share by Twitter from the “More” menu. You can also copy the URL from your browser to share your particular view (location and zoom level).
What is the 'Sprawl Index'?
The sprawl index, or SNDi in our research papers, is our overall measure of street-network sprawl. It stands for the Street Network Disconnectedness Index. A higher SNDi means less-connected streets – i.e., more sprawl.
Under Advanced Controls (or the gear icon), you can choose to display some other measures of sprawl. They all make up part of our Index, and are all described in our research papers.
Changes over time
To see changes over time, open up the Advanced Controls (or gear icon). 'Show Stock' shows all streets (and SNDi) based on all urban streets. 'Show Cumulative' shows all streets (and the corresponding SNDi) built up to a given year, while turning it off shows just the streets (and their SNDi) that were built in a given time period. You can choose the time period with a slider.
We classified local street networks into several types, such as grid, dendritic (tree-like), and circuitous (typical of gated communities). You can visit a randomly-chosen location using this tool.
Which browsers are supported?
Only open source browsers are supported. If you are using a Microsoft browser, please switch to Chrome or Firefox or something else standards-compliant.
Would you like to help?
Yes! We need help with our translations
. All the text needed for this page resides on this Google Doc
. If you can help improve the translations for your language, or add a language, we will be very grateful. See the 'Report an issue' menu item on the main page's main menu for how to contact us with your contribution.
Do you need help?
There is some more help on using the site.
Where can I learn more?
See tables of street-network connectivity By country
or by city for 200 cities
; see the research papers behind the data
; and read about what this means
for citizens and planners, worldwide.