Street-network Sprawl in Central African Republic


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.

Central African Republic

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 Central African Republic on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Central African Republic as of 2014, the overall level of street-network sprawl is 4.12, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.45, 3.89, 4.48 and 4.04. Street construction in Central African Republic 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 Central African Republic spans a total of 21715 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 4.04, which is highly disconnected.

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 3.45, 3.98, 4.11 and 4.12. Overall, the SNDi of the aggregate street network has risen: the street network in Central African Republic has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.53 points, but between 1991-2000 and 2001-2014, it rose by just 0.01.

The level of street-network sprawl in new development in Central African Republic peaked in 1991-2000. To get a sense of how street development has changed in Central African Republic, we can consider three of its most populous regions: Bangui, Mambéré-Kadéï and Haute-Kotto. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Bangui followed a zig-zag trend with an overall increase. The level of street-network sprawl in new development in Mambéré-Kadéï followed a zig-zag trend with an overall increase. The level of street-network sprawl in new development in Haute-Kotto followed a zig-zag trend with an overall increase.

How do development practices in Central African Republic fare in comparison to others in the world? Most recently in 2001-2014, street construction in Central African Republic was the 92nd-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, street construction in Central African Republic has become more connected. Central African Republic ranked 53rd in 1975, 53rd in 1976-1990, 62nd in 1991-2000 and 92nd in 2001-2014.

The largest city in Central African Republic is Bangui, with a population of 1024400 people. Taking into account the entire (i.e. aggregate) street network in Bangui as of 2014, the overall level of street-network sprawl is 2.19, which is relatively well-connected. The level of street-network sprawl in new development in Bangui followed a zig-zag trend with an overall decrease.

As of 2014, the city with the most disconnected street network in Central African Republic is Badokwa with an SNDi of 4.01, which is highly disconnected. Conversely, the most connected city is Nola with an SNDi of 1.12, which is relatively well-connected. See trends for these cities: Nola, Badokwa

The level of street-network sprawl in the aggregate network in Central African Republic rose steadily. To get a sense of how the aggregate street network has changed in Central African Republic, we can consider three of its most populous regions: Bangui, Mambéré-Kadéï and Haute-Kotto. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Bangui rose steadily. The level of street-network sprawl in the aggregate network in Mambéré-Kadéï peaked in 1991-2000. The level of street-network sprawl in the aggregate network in Haute-Kotto followed a zig-zag trend with an overall increase.

To date, Central African Republic is the 48th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has risen; relative to other countries in the world, the street network in Central African Republic has become more disconnected. Central African Republic ranked 53rd in 1975, 45th in 1976-1990, 46th in 1991-2000 and 48th in 2001-2014.

The largest city in Central African Republic is Bangui, with a population of 1024400 people. Taking into account the entire (i.e. aggregate) street network in Bangui as of 2014, the overall level of street-network sprawl is 2.19, which is relatively well-connected. The level of street-network sprawl in the aggregate network in Bangui fell steadily.