Street-network Sprawl in Federal Capital Territory, Nigeria

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.

Federal Capital Territory: region in Nigeria

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 Federal Capital Territory, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Federal Capital Territory as of 2014, the overall level of street-network sprawl is 4.72, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 4.84, 4.35, 4.68 and 4.8. The disconnectivity of new streets constructed in Federal Capital Territory fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Federal Capital Territory spans a total of 8713 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 4.8, 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 4.84, 4.37, 4.57 and 4.72. The SNDi of the aggregate street network in fell at first, but Federal Capital Territory has worsened in disconnectivity since 1990.

The level of street-network sprawl in new development in Federal Capital Territory was at its lowest in 1976-1990. To get a sense of how street development has changed in Federal Capital Territory, we can consider three of its most populous cities: Abuja, Gwagwalada and Rubuchi. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Abuja rose steadily. The level of street-network sprawl in new development in Gwagwalada followed a zig-zag trend. The level of street-network sprawl in new development in Rubuchi followed a zig-zag trend.

How do development practices in Federal Capital Territory fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Federal Capital Territory was the 11th-most disconnected out of the 37 regions in Nigeria. Its position in the ranks since 1975 has fallen; relative to other regions in Nigeria, street construction in Federal Capital Territory has become more connected. Federal Capital Territory ranked 2nd in 1975, 8th in 1976-1990, 10th in 1991-2000 and 11th in 2001-2014.

As of 2014, the city with the most disconnected street network in Federal Capital Territory is Kpeyi with an SNDi of 5.39, which is highly disconnected. Conversely, the most connected city is Abaji with an SNDi of 2.3, which is in the 40th to 60th percentile of disconnectedness. See trends for these cities: Abaji, Kpeyi

The level of street-network sprawl in the aggregate network in Federal Capital Territory was at its lowest in 1976-1990. To get a sense of how the aggregate street network has changed in Federal Capital Territory, we can consider three of its most populous cities: Abuja, Gwagwalada and Rubuchi. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Abuja rose steadily. The level of street-network sprawl in the aggregate network in Gwagwalada followed a zig-zag trend. The level of street-network sprawl in the aggregate network in Rubuchi followed a zig-zag trend.

To date, Federal Capital Territory is the 5th-most disconnected out of the 37 regions in Nigeria. Its position in the ranks since 1975 has fallen; relative to other regions in Nigeria, the street network in Federal Capital Territory has become more connected. Federal Capital Territory ranked 2nd in 1975, 6th in 1976-1990, 7th in 1991-2000 and 5th in 2001-2014.