Street-network Sprawl in Nuevo León, Mexico

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.

Nuevo León: region in Mexico

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 Nuevo León, Mexico on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Nuevo León 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 1.63, 2.07, 2.53 and 3.72. In each period, new street development in Nuevo León steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Nuevo León spans a total of 27190 kilometers. The period with the greatest volume of street construction was 1976-1990. These roads have an SNDi of 2.07, 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 1.63, 1.92, 1.98 and 2.41. Overall, the SNDi of the aggregate street network has risen: the street network in Nuevo León has become more disconnected.

The level of street-network sprawl in new development in Nuevo León rose steadily. To get a sense of how street development has changed in Nuevo León, we can consider three of its most populous cities: Monterrey, San Luis and García. Out of the three cities, San Luis and García do not follow the same trend as the region. The level of street-network sprawl in new development in San Luis followed a zig-zag trend. The level of street-network sprawl in new development in García was at its lowest in 1991-2000.

How do development practices in Nuevo León fare in comparison to others in Mexico? Most recently in 2001-2014, street construction in Nuevo León was the 24th-most disconnected out of the 32 regions in Mexico. Its position in the ranks since 1975 has fallen; relative to other regions in Mexico, street construction in Nuevo León has become more connected. Nuevo León ranked 23rd in 1975, 24th in 1976-1990, 24th in 1991-2000 and 24th in 2001-2014.

As of 2014, the city with the most disconnected street network in Nuevo León is García with an SNDi of 2.26, which is relatively well-connected. Conversely, the most connected city is Cadereyta Jiménez with an SNDi of 1.4, which is relatively well-connected. See trends for these cities: Cadereyta Jiménez, García

The level of street-network sprawl in the aggregate network in Nuevo León rose steadily. To get a sense of how the aggregate street network has changed in Nuevo León, we can consider three of its most populous cities: Monterrey, San Luis and García. Out of the three cities, San Luis and García do not follow the same trend as the region. The level of street-network sprawl in the aggregate network in San Luis followed a zig-zag trend. The level of street-network sprawl in the aggregate network in García was at its lowest in 1991-2000.

To date, Nuevo León is the 24th-most disconnected out of the 32 regions in Mexico. Its position in the ranks since 1975 has fallen; relative to other regions in Mexico, the street network in Nuevo León has become more connected. Nuevo León ranked 23rd in 1975, 26th in 1976-1990, 26th in 1991-2000 and 24th in 2001-2014.