Street-network Sprawl in Centre-Est, Burkina Faso

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.

Centre-Est: region in Burkina Faso

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 Centre-Est, Burkina Faso on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Centre-Est as of 2014, the overall level of street-network sprawl is 2.16, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.79, 1.11, 2.93 and 2.46. Street construction in Centre-Est 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 Centre-Est spans a total of 2506 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.46, 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 -0.79, 1.0, 1.21 and 2.16. Overall, the SNDi of the aggregate street network has risen: the street network in Centre-Est has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.79 points, but between 1991-2000 and 2001-2014, it rose by just 0.95.

The level of street-network sprawl in new development in Centre-Est peaked in 1991-2000. To get a sense of how street development has changed in Centre-Est, we can consider three of its most populous cities: Cinkassé, Tenkodogo and Pouytenga. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Cinkassé followed a zig-zag trend. The level of street-network sprawl in new development in Tenkodogo followed a zig-zag trend. The level of street-network sprawl in new development in Pouytenga followed a zig-zag trend.

How do development practices in Centre-Est fare in comparison to others in Burkina Faso? Most recently in 2001-2014, street construction in Centre-Est was the 2nd-most disconnected out of the 13 regions in Burkina Faso. Its position in the ranks since 1975 has risen; relative to other regions in Burkina Faso, street construction in Centre-Est has become more disconnected. Centre-Est ranked 8th in 1976-1990, 3rd in 1991-2000 and 2nd in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2014, the city with the most disconnected street network in Centre-Est is Pouytenga with an SNDi of 1.82, which is relatively well-connected. Conversely, the most connected city is Koupéla with an SNDi of 0.57, which is relatively well-connected. See trends for these cities: Koupéla, Pouytenga

The level of street-network sprawl in the aggregate network in Centre-Est rose steadily. To get a sense of how the aggregate street network has changed in Centre-Est, we can consider three of its most populous cities: Cinkassé, Tenkodogo and Pouytenga. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Cinkassé followed a zig-zag trend. The level of street-network sprawl in the aggregate network in Tenkodogo followed a zig-zag trend. The level of street-network sprawl in the aggregate network in Pouytenga followed a zig-zag trend.

To date, Centre-Est is the 4th-most disconnected out of the 13 regions in Burkina Faso. Its position in the ranks since 1975 has risen; relative to other regions in Burkina Faso, the street network in Centre-Est has become more disconnected. Centre-Est ranked 7th in 1976-1990, 8th in 1991-2000 and 4th in 2001-2014. There was no ranking in 1975 due to unavailable data.