Street-network Sprawl in Santiago, Chile

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. Well-connected streets – like New York City’s grid – are more walkable and can be served by public transit.

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. A well-connected street network is associated with better outcomes for health, the environment, sustainable consumption, social integration, and equity.

We can quantify how connected street networks are with the Street Network Disconnectedness Index (SNDi).

SNDi -- our measure of street-network sprawl (disconnectedness)

The SNDi is a comprehensive measurement of “sprawl”. It captures:

A higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25.

More information on the sprawl index can be found in these research papers:

To see the state of street-network sprawl across the globe, visit the sprawlmap.

Santiago: city in Región Metropolitana de Santiago, Chile

What exactly constitutes the spatial extent of the city? For these aggregations, we used the Global Human Settlement Layer Urban Center Database (GHS-UCDB) to define the boundaries of the city. These cities -- or urban centers -- cover areas that are densely populated and built-up, and so may extend beyond the spatial borders of these cities that we may be familiar with. The GHS area is shaded in blue.

View Santiago, Chile on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Santiago as of 2014, the overall level of street-network sprawl is 1.76, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.54, 1.77, 2.2 and 3.97. In each period, new street development in Santiago steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Santiago spans a total of 12337 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.54, which is relatively well-connected.

Effect on the aggregate network: New construction in each period adds to the total stock of streets, but does not change streets that have already been built. Therefore, it has a limited effect on the street network as a whole. The SNDis of the aggregate street network in the respective time periods are 1.54, 1.59, 1.64 and 1.76. Overall, the SNDi of the aggregate street network has risen: the street network in Santiago has become more disconnected.

Santiago and Región Metropolitana de Santiago follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these rose steadily.

How do development practices in Santiago fare in comparison to others in Región Metropolitana de Santiago? Most recently in 2001-2014, street construction in Santiago was the 2nd-most disconnected out of the 4 cities in Región Metropolitana de Santiago. Its position in the ranks since 1975 has risen; relative to other cities in Región Metropolitana de Santiago, street construction in Santiago has become more disconnected. Santiago ranked 3rd in 1975, 4th in 1976-1990, 2nd in 1991-2000 and 2nd in 2001-2014.

Santiago and Chile follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these rose steadily.

How do development practices in Santiago fare in comparison to others in Chile? Most recently in 2001-2014, street construction in Santiago was the 13th-most disconnected out of the 33 cities in Chile. Its position in the ranks since 1975 has risen; relative to other cities in Chile, street construction in Santiago has become more disconnected. Santiago ranked 21st in 1975, 21st in 1976-1990, 22nd in 1991-2000 and 13th in 2001-2014.

Santiago and Región Metropolitana de Santiago follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Santiago is the 4th-most disconnected out of the 4 cities in Región Metropolitana de Santiago. Its position in the ranks since 1975 has fallen; relative to other cities in Región Metropolitana de Santiago, the street network in Santiago has become more connected. Santiago ranked 3rd in 1975, 4th in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014.

Santiago and Chile follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Santiago is the 27th-most disconnected out of the 33 cities in Chile. Its position in the ranks since 1975 has fallen; relative to other cities in Chile, the street network in Santiago has become more connected. Santiago ranked 21st in 1975, 25th in 1976-1990, 27th in 1991-2000 and 27th in 2001-2014.

As of 2015, Santiago had a built-up area of 339.53 square kilometers, and a population of 6336005 people.

These are some other cities with approximately the same population:

For some related information about population, urban extent and density, and roads, visit the Atlas of Urban Expansion.