Street-network Sprawl in São João del-Rei, Brazil

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.

São João del-Rei: city in Minas Gerais, Brazil

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 São João del-Rei, Brazil on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in São João del-Rei as of 2014, the overall level of street-network sprawl is 2.41, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.12, 2.56, 4.0 and 3.69. Street construction in São João del-Rei increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in São João del-Rei spans a total of 253 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.56, which is in the 40th to 60th percentile of disconnectedness.

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 1.12, 2.36, 2.4 and 2.41. Overall, the SNDi of the aggregate street network has risen: the street network in São João del-Rei has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.24 points, but between 1991-2000 and 2001-2014, it rose by just 0.0.

São João del-Rei and Minas Gerais do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in São João del-Rei peaked in 1991-2000, while the SNDi of street constructions in Minas Gerais rose steadily.

How do development practices in São João del-Rei fare in comparison to others in Minas Gerais? Most recently in 2001-2014, street construction in São João del-Rei was the 14th-most disconnected out of the 47 cities in Minas Gerais. Its position in the ranks since 1975 has risen; relative to other cities in Minas Gerais, street construction in São João del-Rei has become more disconnected. São João del-Rei ranked 26th in 1975, 15th in 1976-1990, 9th in 1991-2000 and 14th in 2001-2014.

São João del-Rei and Brazil do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in São João del-Rei peaked in 1991-2000, while the SNDi of street constructions in Brazil rose steadily.

How do development practices in São João del-Rei fare in comparison to others in Brazil? Most recently in 2001-2014, street construction in São João del-Rei was the 122nd-most disconnected out of the 348 cities in Brazil. Its position in the ranks since 1975 has risen; relative to other cities in Brazil, street construction in São João del-Rei has become more disconnected. São João del-Rei ranked 163rd in 1975, 81st in 1976-1990, 68th in 1991-2000 and 122nd in 2001-2014.

São João del-Rei and Minas Gerais follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, São João del-Rei is the 14th-most disconnected out of the 47 cities in Minas Gerais. Its position in the ranks since 1975 has risen; relative to other cities in Minas Gerais, the street network in São João del-Rei has become more disconnected. São João del-Rei ranked 26th in 1975, 13th in 1976-1990, 14th in 1991-2000 and 14th in 2001-2014.

São João del-Rei and Brazil follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, São João del-Rei is the 86th-most disconnected out of the 348 cities in Brazil. Its position in the ranks since 1975 has risen; relative to other cities in Brazil, the street network in São João del-Rei has become more disconnected. São João del-Rei ranked 163rd in 1975, 69th in 1976-1990, 79th in 1991-2000 and 86th in 2001-2014.

As of 2015, São João del-Rei had a built-up area of 9.47 square kilometers, and a population of 75148 people.

These are some other cities with approximately the same population: